Reproducing apparatus, reproducing method, reproducing program, and recording medium

ABSTRACT

For a large capacity recording medium, a user interface having high flexibility and enriched representation is accomplished. A flag that represents whether a play item has a multiple angle structure of which the play item is reproduced with a plurality of angles is described. In addition, a flag that represents whether the beginning of each decode unit is an angle switchable point is described. In a seamless multiple angle structure, the current angle can be switched without need to increase the number of interleave units. In a nonseamless multiple angle structure, with the flag, in a predetermined region on the rear end side of each angle, the current angle is prohibited from being switched. Thus, when a play item exits from the multiple angle, discontinuity in the reproduction can be prevented. In addition, with a flag that represents whether a sub play item should be reproduced not in synchronization with a main path, the sub play item of only audio data can be used as a BGM.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a division of and claims the benefit of priorityunder 35 U.S.C. §120 from U.S. application Ser. No. 10/519,422, filedDec. 23, 2004, which is the national stage application ofPCT/JP04/05805, filed Apr. 22, 2004, and claims the benefit of priorityunder 35 U.S.C. §119 from Japanese Patent Application No. 2003-121595,filed Apr. 25, 2003. The entire contents of each of the aboveapplications are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a reproducing apparatus, a reproducingmethod, a reproducing program, and a recording medium that allow a userto interactively operate a program recorded on a large capacityrecording medium such as a blu-ray disc.

2. Background Art

In recent years, as a standard for a recordable disc type recordingmedium that is detachable from a recording and reproducing apparatus, ablu-ray disc standard has been proposed. The blu-ray disc standardprescribes a disc that has a recording medium having a diameter of 12 cmand a cover layer having a thickness of 0.1 mm. The blu-ray discstandard uses a bluish-purple laser having a wavelength of 405 nm and anobjective lens having a numerical aperture of 0.85. The blu-ray discstandard accomplishes a recording capacity of 27 GB (Giga bytes)maximum. As a result, a program of a BS digital high-vision broadcastavailable in Japan can be recorded for two hours or longer withoutdeterioration of picture quality.

As sources (supply sources) of AV (Audio/Video) signals recorded on therecordable optical disc, an analog signal of for example a conventionalanalog television broadcast and a digital signal of for example adigital television broadcast such as a BS digital broadcast will beused. The blu-ray disc standard has established a method for recordingAV signals of such broadcasts.

As a derivative standard of the current blu-ray disc standard, areproduction-only recording medium on which a movie, music, or the likeis prerecorded is being developed. As a disc-shaped recording medium onwhich a movie or music is prerecorded, DVD (Digital Versatile Disc) hasbeen widely used. The reproduction-only optical disc in accordance withthe blu-ray disc standard is largely different from and superior to theconventional DVD in a large recording capacity and a high speed transferspeed that allow a high-vision picture to be recoded for two hours orlonger in high quality.

The current blu-ray disc standard prescribes neither a method fordisplaying a list of video contents of a disc on a screen nor a userinterface function for allowing a user to move a cursor on the list andselect a video content that he or she wants to reproduce from the list.These functions are accomplished by a recording and reproducingapparatus main unit that records and reproduces video contents to andfrom the blu-ray disc. Thus, even if a video content is reproduced fromthe same recording medium, the layout of the contents list screendepends on the recording and reproducing apparatus for use, and so doesthe user interface. Thus, the user cannot easily use the blu-ray disc.Thus, it is necessary to allow the reproduction-only disc to display amenu screen and so forth that the disc (contents) producer has designed,not depend on the reproducing apparatus.

A multiple story function of which a selection screen is displayed whilea video content is being reproduced is generally called an interactivefunction. To accomplish the interactive function, it is necessary forthe disc producer to create a scenario that he or she has designated areproduction order and branches of the video content, describe thescenario using a program language, a script language, or the like, andrecord the described scenario on a disc. The reproducing apparatus sidereads and executes the scenario. As a result, the reproducing apparatusreproduces a video content and displays selection screens that allow theuser to select branches of the video content that the producer hasdesignated.

The current blu-ray disc standard (blu-ray disc rewritable format ver1.0) prescribes neither a method for composing a menu screen and abranch selection screen that a contents producer has designated, nor amethod for describing a process for a user input. Currently, it isdifficult to reproduce a video content from a blu-ray disc in accordancewith a scenario that the producer has designated with compatibilityirrespective of manufactures and models of reproducing apparatuses.

For a reproduction-only disc, the producer side desires a multiple anglefunction for allowing a user to select one of angles of an objectphotographed by a plurality of cameras so that the user can watch theobject at his or her favorite angle. Thus, it is necessary to providesuch a function.

The foregoing interactive function has been already accomplished in forexample the DVD (Digital Versatile Disc) standard. In the DVD video,while a moving picture is being reproduced, a menu screen is calledusing for example a remote control commander. By selecting a buttondisplayed on a menu screen, the user can perform a process for changingthe current scene that is being reproduced. In addition, the DVD videoalso has a multiple angle function.

The user interface and interactive function that have been accomplishedby conventional recording mediums such as DVDs have been also desiredfor large capacity recording mediums such as blu-ray discs asreproduction-only discs.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide areproducing apparatus, a reproducing method, a reproducing program, anda recording medium that allow a user interface with high flexibility fora large capacity recorded medium to be accomplished.

In addition, another object of the present invention is to provide areproducing apparatus, a reproducing method, a reproducing program, anda recording medium that allow an enriched user interface for a largecapacity recorded medium to be accomplished.

To solve the foregoing problem, the present invention is a reproducingapparatus for reproducing content data recorded on a disc shapedrecording medium, the reproducing apparatus comprising: reading meansfor reading from the recording medium a video stream, a first flagdescribed for each reproduction unit of the video stream, the number ofangles that the reproduction unit contains, and position informationthat represents the positions of the angles on the video stream, thefirst flag representing whether or not the reproduction unit can bereproduced with a plurality of angles; and reproducing means forcontrolling the reading means so that the video stream that composes theangles is read in accordance with the position information.

In addition, the present invention is a reproducing method forreproducing content data recorded on a disc shaped recording medium, thereproducing method comprising the steps of: reading from the recordingmedium a video stream, a first flag described for each reproduction unitof the video stream, the number of angles that the reproduction unitcontains, and position information that represents the positions of theangles on the video stream, the first flag representing whether or notthe reproduction unit can be reproduced with a plurality of angles; andcontrolling the reading step so that the video stream that composes theangles is read in accordance with the position information.

In addition, the present invention is a reproducing program that causesa computer device to execute a reproducing method for reproducingcontent data recorded on a disc shaped recording medium, the reproducingmethod comprising the steps of: reading from the recording medium avideo stream, a first flag described for each reproduction unit of thevideo stream, the number of angles that the reproduction unit contains,and position information that represents the positions of the angles onthe video stream, the first flag representing whether or not thereproduction unit can be reproduced with a plurality of angles; andcontrolling the reading step so that the video stream that composes theangles is read in accordance with the position information.

In addition, the present invention is a disc shaped recording medium onwhich a reproducing program that can be read by a computer device hasbeen recorded, the reproducing program causing the computer device toexecute a reproducing method for reproducing content data recorded onthe recording medium, the reproducing method comprising the steps of:reading from the recording medium a video stream, a first flag describedfor each reproduction unit of the video stream, the number of anglesthat the reproduction unit contains, and position information thatrepresents the positions of the angles on the video stream, the firstflag representing whether or not the reproduction unit can be reproducedwith a plurality of angles; and controlling the reading step so that thevideo stream that composes the angles is read in accordance with theposition information.

In addition, the present invention is a disc shaped recording medium onwhich content data has been recorded, wherein a video stream, a firstflag described for each reproduction unit of the video stream, thenumber of angles that the reproduction unit contains, and positioninformation that represents the positions of the angles on the videostream have been recorded on the recording medium, the first flagrepresenting whether or not the reproduction unit can be reproduced witha plurality of angles, and wherein the video stream that composes theangles is read in accordance with the position information.

In addition, the present invention is a reproducing apparatus forreproducing content data recorded on a disc shaped recording medium, thereproducing apparatus comprising: reading means for reading from therecording medium a main stream mainly reproduced, a sub streamreproduced as a sub of the main stream along therewith, and a flag thatrepresents whether or not the sub stream should be repeatedly reproducednot in synchronization with the main stream; and reproducing means forcontrolling the reproduction of the sub stream in accordance with theflag.

In addition, the present invention is a reproducing method forreproducing content data recorded on a disc shaped recording medium, thereproducing method comprising the steps of: reading from the recordingmedium a main stream mainly reproduced, a sub stream reproduced as a subof the main stream along therewith, and a flag that represents whetheror not the sub stream should be repeatedly reproduced not insynchronization with the main stream; and controlling the reproductionof the sub stream in accordance with the flag.

In addition, the present invention is a reproducing program that causesa computer device to execute a reproducing method for reproducingcontent data recorded on a disc shaped recording medium, the reproducingmethod comprising the steps of: reading from the recording medium a mainstream mainly reproduced, a sub stream reproduced as a sub of the mainstream along therewith, and a flag that represents whether or not thesub stream should be repeatedly reproduced not in synchronization withthe main stream; and controlling the reproduction of the sub stream inaccordance with the flag.

In addition, the present invention is a recording medium on which areproducing program that can be read by a computer device has beenrecorded, the reproducing program that causes the computer device toexecute a reproducing method for reproducing content data recorded on adisc shaped recording medium, the reproducing method comprising thesteps of: reading from the recording medium a main stream mainlyreproduced, a sub stream reproduced as a sub of the main stream alongtherewith, and a flag that represents whether or not the sub streamshould be repeatedly reproduced not in synchronization with the mainstream; and controlling the reproduction of the sub stream in accordancewith the flag.

In addition, the present invention is a disc shaped recording medium onwhich content data has been recorded, wherein a main stream mainlyreproduced, a sub stream reproduced as a sub of the main stream alongtherewith, and a flag have been recorded on the recording medium, theflag representing whether or not the sub stream should be repeatedlyreproduced not in synchronization with the main stream, and wherein thereproduction of the sub stream is controlled in accordance with theflag.

In addition, the present invention is a reproducing apparatus forreproducing content data recoded on a disc shaped recording medium, thereproducing apparatus comprising: reading means for reading from therecording medium video data, audio data reproduced in accordance withthe video data, and a flag that represents whether the video data andthe audio data have been recorded as a multiplexed file or independentfiles; and reproducing means for reproducing the video data and theaudio data that are read by the reading means in accordance with theflag that is read by the reading means.

In addition, the present invention is a reproducing method forreproducing content data recoded on a disc shaped recording medium, thereproducing method comprising the steps of: reading from the recordingmedium video data, audio data reproduced in accordance with the videodata, and a flag that represents whether the video data and the audiodata have been recorded as a multiplexed file or independent files; andreproducing the video data and the audio data that are read at thereading step in accordance with the flag that is read at the readingstep.

In addition, the present invention is a reproducing program that causesa computer device to execute a reproducing method for reproducingcontent data recoded on a disc shaped recording medium, the reproducingmethod comprising the steps of: reading from the recording medium videodata, audio data reproduced in accordance with the video data, and aflag that represents whether the video data and the audio data have beenrecorded as a multiplexed file or independent files; and reproducing thevideo data and the audio data that are read at the reading step inaccordance with the flag that is read at the reading step.

In addition, the present invention is a recording medium on which areproducing program that can be read by a computer device has beenrecorded, the reproducing program causing the computer device to executea reproducing method for reproducing content data recoded on a discshaped recording medium, the reproducing method comprising the steps of:reading from the recording medium video data, audio data reproduced inaccordance with the video data, and a flag that represents whether thevideo data and the audio data have been recorded as a multiplexed fileor independent files; and reproducing the video data and the audio datathat are read at the reading step in accordance with the flag that isread at the reading step.

In addition, the present invention is a disc shaped recording medium onwhich content data has been recorded, wherein video data, audio datareproduced in accordance with the video data, and a flag have beenrecorded on the recording medium, the flag representing whether thevideo data and the audio data have been recorded as a multiplexed fileor independent files, and wherein the video data and the audio data thatare read at the reading step are reproduced in accordance with the flagthat is read at the reading step.

As described above, according to the present invention, since a videostream, a first flag that is described in each reproduction unit andthat represents whether or not each reproduction unit can be reproducedwith a plurality of angles, the number of angles of each reproductionunit, and position information that represents the position of eachangle on the video stream have been recorded on the recording medium, avideo stream that composes an angle can be read in accordance withposition information. Thus, while a video stream of each reproductionunit being reproduced, the current angle can be switched to anotherangle.

In addition, according to the present invention, since a main streamthat is mainly reproduced, a sub stream that is reproduced along withthe main stream, and a flag that represents whether or not the substream should be asynchronously and repeatedly reproduced not along withthe main stream are recorded and the reproduction of the sub stream iscontrolled in accordance with the flag, while the main stream is beingreproduced, the sub stream can be asynchronously and repeatedlyreproduced not along with the main stream.

In addition, according to the present invention, since video data, audiodata reproduced in accordance therewith, and a flag that represents atleast whether the video data and audio data have been multiplexedly orindependently recorded are recorded and the video data and audio dataare reproduced in accordance with the flag, the reading method for videodata and audio data can be controlled in accordance with the flag.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram showing a mechanism for designating areproduction order of an AV stream file;

FIG. 2 is a UML diagram showing the relation of a clip AV stream, clipinformation, a clip, a play item, and a play list;

FIG. 3 is a schematic diagram describing a method for referencing thesame clip from a plurality of play lists;

FIG. 4 is a schematic diagram describing a management structure of filesrecorded on a recording medium;

FIG. 5 is a schematic diagram showing a syntax that describes an exampleof a structure of a file “info.bdav”;

FIG. 6 is a schematic diagram showing a syntax that describes an exampleof a structure of a block UIAppInfoBDAV( );

FIG. 7 is a schematic diagram describing a syntax that describes anexample of a structure of a block TableOfPlayLists( );

FIG. 8 is a schematic diagram showing a syntax that describes an exampleof a structure of files “#####.rpls” and “#####.vpls”; FIG. 9 is aschematic diagram showing a syntax that describes an example of astructure of a block UIAppInfoPlayList( );

FIG. 10 is a schematic diagram showing a syntax that describes anexample of a structure of a block PlayList( );

FIG. 11 is a schematic diagram showing a syntax that describes anexample of a structure of a block PlayItem( );

FIG. 12 is a schematic diagram describing a bridge clip;

FIG. 13 is a schematic diagram showing a syntax that describes anexample of a structure of a block PlayListMark( );

FIG. 14 is a schematic diagram showing a syntax that describes anexample of a structure of a file “%%%%%.clpi”;

FIG. 15 is a schematic diagram showing an example of a structure of aplane used as a display system of an image according to an embodiment ofthe present invention;

FIG. 16 is a schematic diagram showing examples of resolutions anddisplayable colors of a moving picture plane, a subtitle plane, and agraphics plane;

FIG. 17 is a block diagram showing an example of a structure thatcombines the moving picture plane, the subtitle plane, and the graphicsplane;

FIG. 18 is a schematic diagram showing an example of input and outputdata of a palette;

FIG. 19 is a schematic diagram showing an example of a palette tableheld in a palette;

FIG. 20 is a schematic diagram showing an example of a menu screendisplayed on the graphics plane;

FIG. 21 is a schematic diagram showing an example of an internalstructure of a scenario in accordance with an originally definedscenario descriptive language;

FIG. 22 is a schematic diagram describing categories of a structure of ascenario;

FIG. 23A, FIG. 23B, and FIG. 23C are schematic diagrams describingcategories of structures of scenarios;

FIG. 24 is a schematic diagram describing titles and chapters;

FIG. 25 is a schematic diagram describing a BD virtual player model;

FIG. 26A and FIG. 26B are flow charts schematically describing anoperation of a BD virtual player 30 in accordance with commandsdescribed in a scenario;

FIG. 27A and FIG. 27B are flow charts describing reproducing operationsin accordance with play lists;

FIG. 28A, FIG. 28B, FIG. 28C, FIG. 28D, FIG. 28E, FIG. 28F, FIG. 28G,and FIG. 28H are schematic diagrams showing examples of commands used ina scenario;

FIG. 29 is a schematic diagram showing an example of a file managementstructure;

FIG. 30 is a schematic diagram showing a syntax that describes anexample of a structure of a file “scenario.hdmv”;

FIG. 31 is a schematic diagram showing a syntax that describes anexample of a data structure of a block Autoplay( );

FIG. 32 is a schematic diagram showing a syntax that describes anexample of a structure of a block Scenario( );

FIG. 33 is a schematic diagram showing a syntax that describes anexample of a data structure of a file “entrylist.data”;

FIG. 34 is a schematic diagram showing a syntax that describes anexample of a structure of a block AppInfo( );

FIG. 35 is a schematic diagram showing a syntax that describes anexample of a structure of a block ScenarioEntry( );

FIG. 36 is a schematic diagram showing a syntax that describes anexample of a structure of a file “xxxx.mpls”;

FIG. 37 is a schematic diagram showing a syntax that describes anexample of a structure of a block PLCpntrolInfo( );

FIG. 38 is a schematic diagram that describes a field PL_Playback_type;

FIG. 39 is a schematic diagram that describes a fieldPL_random_access_mode;

FIG. 40 is a schematic diagram showing a syntax that describes anexample of a structure of a block PlayList( );

FIG. 41 is a schematic diagram showing a syntax that describes anexample of a structure of a block PlayItem( );

FIG. 42 is a schematic diagram describing a field PI_random_access_mode;

FIG. 43 is a schematic diagram describing a field still_mode;

FIG. 44 is a schematic diagram describing a fieldis_seamless_angle_change;

FIG. 45 is a schematic diagram showing a syntax that describes anexample of a structure of a block SubPlayItem( );

FIG. 46 is a schematic diagram describing a field is_repeat_flag;

FIG. 47 is a schematic diagram describing a synchronous reproduction fora sub play item in accordance with a main play item;

FIG. 48 is a schematic diagram showing a syntax that describes anexample of a structure of a file “zzzzz.clpi”;

FIG. 49 is a schematic diagram showing a syntax that describes anexample of a structure of a block ClipInfo( );

FIG. 50 is a schematic diagram describing a field application_type;

FIG. 51 is a schematic diagram showing a syntax that describes anexample of a structure of a block SequenceInfo( );

FIG. 52 is a schematic diagram showing a syntax that describes anexample of a structure of a block ProgramInfo( );

FIG. 53 is a schematic diagram showing a syntax that describes anexample of a structure of a block StreamCodingInfo( );

FIG. 54 is a schematic diagram showing a syntax that describes anexample of a structure of a block CPI( );

FIG. 55 is a schematic diagram describing a field CPI_type;

FIG. 56 is a schematic diagram showing a syntax that describes anexample of a structure of a block EP_map_for_HDMV( );

FIG. 57 is a schematic diagram describing an extent;

FIG. 58 is a schematic diagram showing an example of which a clip AVstream has been fragmentally recorded on a disc;

FIG. 59A and FIG. 59B are schematic diagrams describing a multiple anglefunction;

FIG. 60A and FIG. 60B are schematic diagrams showing a plurality ofangle switchable points described in one interleave unit;

FIG. 61 is a schematic diagram describing a flag is_angle_change_point;

FIG. 62A and FIG. 62B are schematic diagrams showing an example of anonseamless multiple angle block;

FIG. 63A and FIG. 63B are schematic diagrams describing that when anangle is switched in a nonseamless multiple angle block, a discontinuitytakes place;

FIG. 64A and FIG. 64B are schematic diagrams describing a firstreproducing method for a nonseamless multiple angle block;

FIG. 65A and FIG. 65B are schematic diagrams describing a secondreproducing method for a nonseamless multiple angle block; and

FIG. 66A, FIG. 66B, and FIG. 66C are a functional block diagram showingan example of a structure of a player decoder 100 according to anembodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Next, an embodiment of the present invention will be described.According to an embodiment of the present invention, based on theblu-ray disc standard (blu-ray disc rewritable format ver 1.0), which isa standard for recording and reproducing data, functions necessary for areproduction-only disc such as an interactive function and a multipleangle function are accomplished.

First of all, for easy understanding of the present invention, amanagement structure as prescribed in “Blu-ray Disc Rewritable FormatVer 1.0 part 3 Audio Visual Specification) for contents namely AV(Audio/Video) data prerecorded on a blu-ray disc will be described. Inthe following description, the management structure is referred to asBDAV format.

A bit stream that has been encoded in accordance with an encoding systemsuch as MPEG (Moving Pictures Experts Group) video or MPEG audio andmultiplexed in accordance with MPEG-2 system is referred to as clip AVstream (or simply AV stream). The clip AV stream is recorded as a fileon a disc by a file system defined in “Blu-ray Disc Rewritable FormatVer 1.0 part 2” for a blu-ray disc. This file is referred to as clip AVstream file (or simply AV stream).

A clip AV stream file is a management unit on the file system. Thus, itcannot be said that a clip AV stream file is a management unit that theuser can easily understand. From a view point of user's convenience, itis necessary to record information necessary for combining a videocontent that has been divided into a plurality of clip AV stream filesand reproducing the combined video content, information necessary forreproducing only a part of a clip AV stream file, information necessaryfor smoothly performing a special reproduction and a searchreproduction, and so forth as a database. “Blu-ray Disc RewritableFormat Ver. 1.0 part 3” as a standard for a blu-ray disc prescribes sucha database.

FIG. 1 schematically shows a mechanism for designating a part of all anAV stream file, arranging only desired portions thereof, and reproducingthe arranged portions. In FIG. 1, a play list (PlayList) causes a partor all an AV stream file to be designated and only desired portionsthereof to be reproduced. When the user reproduces a content, he or sheselect it in the unit of a play list. A play list is one video/audiounit in which the user implicitly expects that a content will besuccessively reproduced.

The simplest structure of a play list is composed of one AV stream fileafter recording of a content is started until the recording is stopped.Unless the AV stream file is edited, it becomes one play list

A play list is composed of information that represents an AV stream fileto be reproduced and sets of reproduction start points and reproductionstop points that designate reproduction start positions and reproductionstop positions of the AV stream file. A pair of information of areproduction start point and information of a reproduction stop point isreferred to as play item (PlayItem). A play list is composed of a set ofplay items. When a play item is reproduced, a part of the AV stream filereferred from the play item is reproduced.

As described above, a clip AV stream is a bit stream of which video dataand audio data have been multiplexed in the format of an MPEG2 TS(Transport Stream). Information about the clip AV stream is recorded asclip information to a file.

A set of a clip AV stream file and a clip information file that hascorresponding clip information is treated as one object and referred toas clip. A clip is one object that is composed of a clip AV stream andclip information.

A file is generally treated as a sequence of bytes. A content of a clipAV stream file is expanded on the time base. An entry point in a clip isregularly designated on the time base. When a time stamp of an accesspoint to a predetermined clip is given, a clip information file can beused to find information of an address from which data is read in a clipAV stream file.

All play lists and clips recorded on one disc are managed with volumeinformation.

FIG. 2 shows a UML (Unified Modeling Language) diagram that representsthe relation of the foregoing clip AV stream, clip information (streamattributes), clips, play items, and play list. One play list iscorrelated with one or a plurality of play items. One play item iscorrelated with one clip. One clip may be correlated with a plurality ofplay items whose start points and/or end points are different. One clipAV stream file is referenced from one clip. One clip information file isreferenced from one clip. One clip AV stream file and one clipinformation file are correlated with the relation of one to one. Withsuch a structure defined, a reproduction order can be non-destructivelydesignated by reproducing only any part, not changing a clip AV streamfile.

As shown in FIG. 3, the same clip can be referenced from a plurality ofplay lists. In the example shown in FIG. 3, a clip 1 is referenced fromtwo play lists 2 and 3. In FIG. 3, the horizontal direction of the clip1 represents the time base. The play list 2 references regions a to f ofthe clip 1 that include commercial message regions b and c and a scenee. The play list 3 references regions d to g of the clip 1 that includea scene e. When the play list 2 is designated, the regions a to f of theclip 1 can be reproduced. When the play list 3 is designated, theregions d to g of the clip 1 can be reproduced.

Next, with reference to FIG. 4, a management structure for filesrecorded on a recording medium prescribed in “Blu-ray Disc RewritableFormat Ver 1.0 part 3” will be described. Files are hierarchicallymanaged in a directory structure. One directory (a root directory in theexample shown in FIG. 4) is created on the recording medium. Under thedirectory, files are managed by one recording and reproducing system.

Under the root directory, a directory BDAV is placed. As shown in FIG.4, a plurality of directories such as directories BDAV, BDAV1, BDAV2, .. . , BDAVn can be placed. In the following description, the pluralityof directories BDAV, BDAV1, BDAV2 . . . , and BDAVn are represented bythe directory BDAV. Only the representative directory BDAV will bedescribed.

Under the directory BDAV, the following six types of files are placed.

-   (1) info.bdav-   (2) menu.tidx, mark.tidx-   (3) menu.tdt1, menu.tdt2, mark.tdt1, mark.tdt2-   (4) #####H#.rpls, #####.vpls-   (5) %%%%%.clpi-   (6) *****.m2ts

In the files “#####.rpls” and “#####.vpls” categorized as (4), “#####represents any number. In the file “%%%%%.clpi” categorized as (5),“%%%%%” represents any number. In the file “*****.m2ts” categorized as(6), “***** represents a number of which a file “*****.m2ts” correspondsto a file “%%%%%.clpi” with the relation of one to one. A number “*****”can be the same as a number “%%%%%”.

The file “info.bdav” categorized as (1) is a file that has informationof all the directory BDAV. The files “menu.tidx” and “mark.tidx”categorized as (2) are files that have information of thumbnailpictures. The files “menu.tdt1”, “menu.tdt2”, “mark.tdt1”, and“mark.tdt2” categorized as (3) are files that have thumbnail pictures.The extensions “tdt1” and “tdt2” of those files represent whether or notdata of thumbnail pictures in those files have been encrypted.

The files “#####.rpls” and “#####.vpls” categorized as (4) are filesthat have information of play lists. The files “#####.rpls” and“#####.vpls” are placed under the directory PLAYLIST, which is placedunder the directory BDAV.

The file “%%%%%.clpi” categorized as (5) is a file that has clipinformation. The file “%%%%%.CLP” is placed under the directory CLIPINF,which is placed under the directory BDAV. The file “*****.m2ts”categorized as (6) is a clip AV stream file that has a clip AV stream. Aclip AV stream file is correlated with one clip information file“%%%%%.clpi” with a file name number “*****”. The file “*****.m2ts” isplaced under the directory STREAM, which is placed under the directoryBDAV.

Next, each file will be described in detail. The file “info.bda”categorized as (1) is only one file placed under the directory BDAV.FIG. 5 shows a syntax that describes an example of a structure of thefile “info.bdav”. The syntax is represented by a descriptive method of Clanguage, which is used as a program descriptive language for computerdevices. This applies to drawings that show other syntaxes.

In FIG. 5, the file “info.bdav” is divided into blocks corresponding tofunctions. A field type_indicator describes a character string “BDAV”that describes that the file is “info.bdav”. A field version_numberrepresents a version of the file “info.bdav”. A block UIAppInfoBDAVOdescribes information about information placed under the directory DBAV.A block TableOfPlayList( ) describes information about the arrangementof the play list. A block MakersPrivateData( ) describes uniqueinformation of the maker of the recording and reproducing apparatus.

Addresses that represent the beginnings of individual blocks aredescribed at the beginning of the file “info.bdav”. For example, a fieldTableOfPlayLists_Start_address represents the start position of theblock “TableOfPlayLists( )” with the number of relative bytes in thefile.

FIG. 6 shows a syntax that describes an example of a structure of ablock UIAppInfoBDAV( ). A field length represents the length immediatelyafter the field length until the end of the block UIAppInfoBDAV( ) inbytes. A field BDAV_character_set represents a character set of acharacter sequence described in a field BDAV_name of the blockUIAppInfoBDAV( ). As a character set, ASCII, Unicode, or the like can beselected.

A flag BDAV_protect_flag describes whether or not the user isunconditionally permitted to watch a content placed under the directoryBDAV. When the flag has been set to “1” and the user has input a correctPIN (Personal Identification Number), he or she is permitted to watch acontent placed under the directory BDAV. In contrast, when the flagBDAV_protect_flag has been set to “0”, even if the user does not inputhis or her PIN, he or she is permitted to watch a content placed underthe directory BDAV.

The personal identification number PIN is described in a field PIN. Thepersonal identification number PIN is composed of for example afour-digit number, each digit ranging from 0 to 9. The personalidentification number PIN represents a personal identification numberthat is required when the reproduction control is validated. Digits ofthe personal identification number PIN are encoded in accordance withfor example ISO (International Organization for Standardization)/IEC(International Electrotechnical Commission) 646 standard.

With the foregoing information described in the block UIAppInfoBDAV( ),the reproduction restriction for the directory BDAV is prescribed. Aswill be described later, the reproduction restriction for each play listis prescribed with a flag playback_control_flag defined in the blockUIAppInfoPlayList( ) described in the files “#####.rpls” and“#####.vpls”.

In the example, to resume reproducing a content placed under thedirectory BDAV, a resume function can be used. The resume functionallows a play list of a content to be reproduced in priority to bedesignated. It is assumed that the resume function is used when the userwants to resumes reproducing a content from the last stop position.

In FIG. 6, a flag resume_valid_flag describes whether the resumefunction is valid/invalid. When the value of the flag has been set to“0”, the resume function is invalid. When the value of the flag has beenset to “1”, the resume function is valid. At that point, a play listdesignated by a field resume_PlayList_file_name is treated as a playlist to be reproduced in priority.

A field ref_to_menu_thumbnail_index is a region that describes athumbnail number that identifies a thumbnail picture that typifies thedirectory BDAV. In the blu-ray disc standard, a still picture thattypifies the directory BDAV is referred to as menu thumbnail. Athumbnail picture that has an index thumbnail_index described in thefield ref_to_menu_thumbnail_index is the menu thumbnail of the directoryBDAV.

A field BDAV_name_length represents the byte length of the name of thedirectory BDAV described in a field BDAV_name. The number of bytesrepresented in the field BDAV_name_length is valid for the characterstring of the field BDAV_name that represents the name of the directoryBDAV. The rest of the byte sequence after the valid character stringrepresented by the field BDAV_name_length may have any value.

FIG. 7 shows a syntax that describes an example of a structure of ablock TableOEPlayLists( ). A field number_of_PlayLists represents thenumber of play lists placed under the directory BDAV. The number of playlists is referred to as loop variable. The field number_of_PlayLists isfollowed by a loop of a “for” statement. The “for” statement describesplay lists represented by a field PlayList_file_name. The play lists aredisplayed on a play list table display screen or the like. A play listis designated with a file name such as “#####.rpls” or “#####.vpls” inthe field PlayList_file_name.

As described above, the files “#####.rpls” and “#####.vpls” are placedunder the directory PLAYLIST. These files correspond to individual playlists in the relation of one to one.

FIG. 8 shows a syntax that describes an example of a structure of thefiles “#####.rpls” and “#####.VPLS”. In FIG. 8, the files “#####.rpls”and “#####.vpls” each have blocks corresponding to functionalinformation. A field type_indicator describes a character string thatrepresents the file. A field version_number represents a version of thefile.

A block UIAppInfoPlayList( ) describes attribute information of the playlist. A block PlayList( ) describes information about play items thatcompose the play list. A block PlayListMark( ) describes informationabout a mark added to the play list. A block MakersPrivateData( )describes maker's unique information of the apparatus that has recordedthe play list file. Fields PlayList_start_address,PlayListMark_start_address and MakersPrivateData_start_address areplaced at the beginning of each of the files “#####.rpls” and“#####.vpls”. These fields describe the start addresses of thecorresponding blocks as address information of 32 bits.

Since the start address of each block is described at the beginning ofeach of the files “#####.rpls” and “#####.vpls”, data padding_word ofany length can be placed before each block and/or after each block.However, the start position of the block UIAppInfoPlayList( ), which isthe first block of each of the files “#####.rpls” and “#####.vpls”, isfixed at the 320-th byte from the beginning of each of these files.

FIG. 9 shows a syntax that describes an example of a structure of ablock UIAppInfoPlayList( ). The block UIAppInfoPlayList( ) describesvarious types of attribute information about the play list. Theattribute information is not directly used for reproducing the playlist. A field PlayList_character_set describes a character set ofcharacter string information about the play list.

A flag playback_control_flag describes whether or not display ofinformation and reproduction of a play list are restricted in accordancewith a personal identification number PIN. When the value of the flagplayback_control_flag is for example “1”, unless the user inputs acorrect personal identification number PIN, information such as athumbnail picture of a play list cannot be displayed and the play listcannot be reproduced. A flag write_protect_flag is an erase prohibitionflag. It is necessary to structure the user interface so that when thevalue of the flag write_protect_flag is “1”, the user cannot easilyerase the play list. A flag is_played_flag describes that the play listhas been reproduced. A flag is_edited_flag describes that the play listhas been edited.

A field time_zone represents a time zone of which the play list wasrecorded. A field record_time_and_date represents the date and time onand at which the play list was recorded. A field PlayList_durationrepresents the reproduction duration of the play list.

Fields maker_ID and maker_model_code describe information thatidentifies a maker and a model of the recording apparatus that lastupdated the play list. The fields maker_ID and maker_model_code are forexample numbers. A field channel_number represents a channel number of arecorded clip AV stream. A field channel_name represents a channel name.A field channel_name_length represents the length of the channel namedescribed in the field channel_name. In the field channel_name, acharacter string having the length described in the fieldchannel_name_length is valid. A field PlayList_name represents a playlist name having an effective length of a value described in the fieldPlayList_name_length. A field PlayList_detail describes detailedinformation of the play list having an effective length of a valuedescribed in the field PlayList_detail_length.

FIG. 10 shows a syntax that describes an example of a structure of ablock PlayList( ). A field length describes the length of bytesimmediately after the field length until the end of the block PlayList(). A field PL_CPI_type describes the type of CPI (Characteristic PointInformation) of the play list. A field number_of_PlayItems describes thenumber of play items that compose the play list. A fieldnumber_of_SubPlayItems describes the number of play items forafter-recording audio (sub play items) added to the play list. In short,a play list can have a sub play item when the play list satisfies apredetermined condition.

A block PlayItem( ) describes information of a play item. A blockSubPlayItem( ) describes information of a sub play item.

FIG. 11 shows a syntax that describes an example of a structure of ablock PlayItem( ). A field Clip_Information_file_name describes acharacter string of a file name of a clip information file (that is afile having an extension clpi) has the relation of one to one with aclip that the play item references. The clip information file is a filehaving an extension “clpi”.

A field Clip_codec_identifier describes an encoding system of a clipthat the play item references. In the example, the fieldClip_codec_Identifier is fixed to a value “M2TS”. A fieldconnection_condition describes information of how this play item isconnected to the next play item. The field connection_conditiondescribes whether or not play items can be seamlessly reproduced.

A field ref_to_STC_id designates a sequence STC_sequence of a clip thatthe play item references. The sequence STC_sequence is a uniquestructure of the blu-ray disc standard. The structure represents a rangeof which a PCR (Program Clock Reference) that is a reference of an MPEG2TS (Transport Stream) is continuous on the time base. A number STC_idthat is unique in the clip is assigned to the sequence STC_sequence. Inthe sequence STC_sequence, since a continuous time base can be defined,the start time and end time of a play item can be uniquely designated.The start point and end point of each play item should exist in the samesequence STC_sequence. A field ref_to_STC_id describes a sequenceSTC_sequence with a number STC_id.

Fields IN_time and OUT_time describe time stamps pts(presentation_time_stamp) of the start point and end point of the playitem in the sequence STC_sequence, respectively.

A block BridgeSequenceInfo( ) describes information about a bridge clip(Bridge_Clip). As shown in FIG. 12, a bridge clip is a bit stream thatis created when a function for seamlessly reproducing play items isaccomplished. By reproducing a bridge clip instead of an original bitstream at a boundary of the preceding play item and the current playitem, the two play items can be seamlessly reproduced. Since thefunction of the bridge clip does not relate to the present invention,the description will be omitted.

FIG. 13 shows a syntax that describes an example of a structure of ablock PlayListMark( ). The block PlayListMark( ) has a data structurethat describes information of a mark. A mark is a structure thatdescribes time of a play list. With a mark, a function for setting asearch point to a play list, a function for dividing a play list intochapters, and so forth are accomplished.

Timing of display start and display stop of a picture on a graphicsplane (that will be described later) can be designated with a mark.

A field length describes the length of bytes immediately after the fieldlength until the end of the block PlayListmark( ). A fieldnumber_of_PlayList_marks describes the number of marks in a play list.One loop of a “for” statement represents information of one mark. A flagmark_invalid_flag describes whether or not the mark is valid. When thevalue of the flag mark_invalid_flag is “0”, it describes that the markis valid. When the value of the flag mark_invalid_flag is “1”, itdescribes that although information of the mark exists in the database,the mark is an invalid mark that is transparent to the user.

A field mark_type describes the type of the mark. There are a mark thatrepresents the position of a picture as a thumbnail picture(representative picture) of the play list, a resume mark that representsa position from which reproduction is resumed, a chapter mark thatrepresents a search point, a skip mark that represents a region to beskipped and reproduced, a mark that represents read start timing of agraphics image, a mark that represents display start timing of agraphics image, a mark that represents display stop timing of a graphicsimage, and so forth.

A field mark_name_length represents a data length of a field mark_name(that will be described later). A field maker_ID describes a maker of arecording apparatus that created the mark. The field maker_ID is used toidentify a mark unique to a maker. A field ref_to_PlayItem_id describeswhat play item has time designated by the mark. A field mark_time_stamprepresents time designated by the mark.

A field entry_ES_PID describes what elementary stream the mark was added(namely, whether the mark was added to a stream of which picture dataand/or sound data was encoded). A field ref_to_menu_thumbnail_index anda field ref_to_mark_thumbnail_index describe thumbnail pictures thatvisually represent marks. A thumbnail picture is for example a stillpicture that was extracted at time designated by the mark.

A field duration is used when a mark has a length on the time base. Whena skip mark is used, the field duration describes for what duration theskip is performed.

A field makers_information is a region that describes information uniqueto the maker. A field mark_name is a region that describes a name thatis assigned to a mark. The size of a mark is described in the foregoingfield mark_name_length.

FIG. 14 shows a syntax that describes an example of a structure of afile “%%%%%.clpiYY. As described above, the file “%%%%%.clpi” is placedunder the directory CLIPINF. The file “%%%%%.clpi” is created for eachAV stream file (file “*****.m2ts”). The file “%%%%%.clpi” has blockscorresponding to functional information. A field type_indicatordescribes a character string that represents the file. A fieldversion_number describes a version of the file.

A block ClipInfo( ) describes information about a clip. A blockSequenceInfo( ) describes information about an incontinuous point of PCRthat represents a time reference of a transport stream of the MPEG2system. A block ProgramInfo( ) describes information about a program ofthe MPEG2 system. A block CPI( ) describes information aboutcharacteristic point information CPI that represents a characteristicportion in an AV stream. A block ClipMark( ) describes mark informationthat represents a search index point added to a clip and commercialstart and/or end points. A block MakersPrivateData( ) describesinformation unique to a maker of a recording apparatus.

Address information that represents the beginning of each block in thefile “%%%%%.clpi” is described as fields SequenceInfo_start_address,ProgramInfo_start_address, CPI_start_address, ClipMark_start_address,and MakersPrivateData_start_address. Since the clip file “%%%%%.clpi”does not relate to the present invention, the description will beomitted.

Since the BDAV format has the foregoing data structure, with a play listcomposed of play items that describe sets of start points and end pointsof portions to be reproduced in a clip AV stream, contents recorded onthe disc can be managed in a reproduction unit that the user canrecognize.

Next, an embodiment of the present invention will be described.According to the present invention, the foregoing BDAV format isextended for a format of a reproduction-only disc. First, a structure ofa plane that accomplishes a menu screen for the contents of a disc willbe described. Next, a scenario structure that allows the contentsproducer side to designate the reproduction order of a play list isadded. For the scenario structure, data necessary for accomplishingfunctions such as a still (pause), a random shuffle reproduction, amultiple angle, and so forth that are characteristics of thereproduction-only disc and a method for storing such data will bedescribed.

According to the embodiment of the present invention, a plane structureas shown in FIG. 15 is used. A moving picture plane 10 is displayed onthe rearmost side (bottom). The moving picture plane 10 deals with apicture (mainly, moving picture data) designated by a play list. Asubtitle plane 11 is displayed above the moving picture plane 10. Thesubtitle plane 11 deals with subtitle data displayed while a movingpicture is being reproduced. A graphics plane 12 is displayed on themost front. The graphics plane 12 deals with character data for a menuscreen and graphics data such as bit map data for buttons. One displayscreen is composed of these three planes.

The difference between the embodiment of the present invention and theconventional DVD video is in that sub pictures for subtitles, a menuscreen, buttons, and so forth are separated into the subtitle plane 11and the graphics plane 12 so that the subtitles and buttons areindependently controlled. In the conventional DVD video, graphics suchas a menu screen and buttons and subtitles are controlled by the samemechanism. They are displayed on the same plane. The number of bit mappictures that can be displayed at the same time is limited to one. Thus,in the DVD video, a plurality of bit map pictures cannot be displayed atthe same time. In contrast, according to the present invention, sincethe subtitle plane 11 and the graphics plane 12 are independentlydisposed for subtitles and graphics, respectively, the foregoing problemof the conventional DVD can be solved.

It can be thought that the subtitle plane 11 and the graphics plane 12are an extension portion of conventional “Blu-ray Disc Rewritable FormatVer 1.0 part 3”.

The moving picture plane 10, the subtitle plane 11, and the graphicsplane 12 can be independently displayed. The moving picture plane 10,the subtitle plane 11, and the graphics plane 12 have resolutions anddisplay colors as shown in FIG. 16. The moving picture plane 10 has aresolution of 1920 pixels×1080 lines, a data length of 16 bits perpixel, a color system of YCbCr (4:2:2), where Y represents a luminancesignal and Cb and Cr represent color difference signals. YCbCr (4:2:2)is a color system having a luminance signal Y of eight bits per pixeland color difference signals Cb and Cr of eight bits each. With twohorizontal pixels of the color difference signals Cb and Cr, data of onecolor data is composed.

The graphics plane 12 has a resolution of 1920 pixels×1080 lines, asampling depth of eight bits per pixel, and a color system of eight-bitcolor map addresses using a palette of 256 colors. The subtitle plane 11has a resolution of 1920 pixels×1080 lines, a sampling depth of eightbits per pixel, and a color system having eight-bit color map addressesusing a palette of 256 colors.

The graphics plane 12 and the subtitle plane 11 can be alpha-blended in256 levels. When the graphics plane 12 and the subtitle plane 11 arecombined with another plane, the transparency can be set in 256 levels.The transparency can be set for each pixel. In the followingdescription, the transparency a is represented in the range of (0□α□1)where transparency α=0 represents perfect transparent; transparency α=1represents perfect in transparent.

The subtitle plane 11 deals with picture data of PNG (Portable NetworkGraphics) format. Likewise, the graphics plane 12 can deal with picturedata of the PNG format. In the PNG format, the sampling depth of onepixel is in the range from one bit to 16 bits. When the sampling depthis eight bits or 16 bits, an alpha channel, namely transparencyinformation (referred to as alpha data) of each pixel component can beadded. When the sampling depth is eight bits, transparency can bedesignated in 256 levels. With the transparency information of the alphachannel, alpha-blending is performed. A palette image of up to 256colors can be used. An element (index) of the prepared palette can berepresented with an index number.

Picture data dealt with the subtitle plane 11 and the graphics plane 12is not limited to the PNG format. Alternatively, picture data that hasbeen compression-encoded in accordance with for example JPEG system,picture data that has been run-length-compressed, or bit map data thathas not been compression-encoded may be used.

FIG. 17 shows an example of a structure of which three planes arecombined with reference to FIG. 15 and FIG. 16. Moving picture data ofthe moving picture plane 10 is supplied to a 422/444 converting circuit20. The 422/444 converting circuit 20 converts the color system of themoving picture data from YCbCr (4:2:2) into YCbCr (4:4:4) and inputs theconverted data to a multiplying device 21.

Picture data of the subtitle plane 11 is input to a palette 22. Thepalette 22 outputs picture data of RGB (4:4:4). When transparency ofalpha-blending is designated, designated transparency α1 (0□α1□1) isoutput from the palette 22.

FIG. 18 shows an example of input/output data of the palette 22. Thepalette 22 holds palette information as a table corresponding to forexample a PNG format file. An index number is referenced as an addressof picture data of input data of eight bits from the palette 22. Inaccordance with the index number, data of RGB (4:4:4) composed of dataof eight bits each is output. In addition, data of the alpha-channelthat represents transparency is obtained from the palette 22.

FIG. 19 shows an example of a palette table that the palette 22 has 256color index values [0x00] to [0xFF] (where [0x] represents hexadecimalnotation) are assigned three primary color values R, G, and B andtransparency α each of which is represented with eight bits. The palette22 references the palette table in accordance with the input PNG formatpicture data and outputs data of colors R, G, and B (RGB data) andtransparency cc of eight bits each for each pixel in accordance with anindex value designated by the picture data.

The RGB data that is output from the palette 22 is supplied to anRGB/YCbCr converting circuit 29. The RGB/YCbCr converting circuit 29converts the RGB data into a luminance signal Y and color differencesignals Cb and Cr of eight bits each (hereinafter, they together arereferred to as YCbCr data). This is because data of planes should becombined in the common data format. Data is unified to YCbCr data thatis the data format of moving picture data.

The YCbCr data and the transparency data α1 that are output from theRGB/YCbCr converting circuit 29 are input to a multiplying device 23.The multiplying device 23 multiplies the input YCbCr data by thetransparency data α1. The multiplied result is input to one inputterminal of an adding device 24. The multiplying device 23 multiplieseach of the luminance signal Y and the color difference signals Cb andCr of the YCbCr data by the transparency data α1. A complement (1−α1) ofthe transparency data α1 is supplied to the multiplying device 21.

The multiplying device 21 multiplies the moving picture data that isinput from the 422/444 converting circuit 20 by the complement (1−α1) ofthe transparency data α1. The multiplied result is input to the otherinput terminal of the adding device 24. The adding device 24 adds themultiplied results of the multiplying device 21 and the multiplyingdevice 23. As the result, the moving picture plane 10 and the subtitleplane 11 are combined. The added result of the adding device 24 is inputto a multiplying device 25.

Like the subtitle plane 11, data of RGB (4:4:4) is output as picturedata of the graphics plane 12 from the palette table 26A and input to anRGB/YCbCr converting circuit 26B. When the color system of picture dataof the graphics plane 12 is RGB (4:4:4), it is converted into YCbCr(4:4:4) and output from an RGB/YCbCr converting circuit 27. The YCbCrdata that is output from the RGB/YCbCr converting circuit 27 is input toa multiplying device 28.

When picture data of the graphics plane 12 is the PNG format,transparency data α2 (0≦α2≦1) can be designated by each pixel in thepicture data. The transparency data α2 is supplied to the multiplyingdevice 28. The multiplying device 28 multiplies each of the luminancesignal Y and the color difference signals Cb and Cr of the YCbCr datathat is input from the RGB/YCbCr converting circuit 27 by thetransparency data α2. The multiplied result of the multiplying device 28is input to one input terminal of an adding device 29. A complement(1−α2) of the transparency data α2 is supplied to the multiplying device25.

The multiplying device 25 multiplies the added result of the addingdevice 24 by the complement (1−α2) of the transparency data α2. Themultiplied result of the multiplying device 25 is input to the otherinput terminal of the adding device 27. The adding device 27 adds themultiplied results of the multiplying device 25 and the multiplyingdevice 28. As a result, the graphics plane 12 and the combined result ofthe moving picture plane 10 and the subtitle plane 11 are combined.

When the transparency a of a non-picture region of the subtitle plane 11and the graphics plane 12 is designated to 0 (α=0), a plane below thoseplanes 11 and 12 becomes transparent. As a result, moving picture dataon the moving picture plane 10 can be displayed as a background of thesubtitle plane 11 and the graphics plane 12.

The structure shown in FIG. 17 can be accomplished by hardware orsoftware.

With the foregoing planes designated, a menu screen and buttonsnecessary for the reproduction-only disc standard can be displayed. Whena button is selected on the menu screen, a play list corresponding tothe button is reproduced. At that point, information about a link ofplay lists should have been recorded on a disc. A scenario that definesa link of play lists will be described.

A screen that prompts the user to perform an operation, for example, amenu screen, can be displayed on the graphics plane 12. FIG. 20 shows anexample of a menu screen 60 displayed on the graphics plane 12. On themenu screen 60, characters and images are displayed at particularpositions. With the characters and images, “links” and “buttons” thatallow the user to select to new operations can be placed.

A “link” describes an access method to a predetermined file with acharacter string or image data. When the user designates the characterstring or image data on a screen with for example a pointing device, heor she can access the predetermined file in accordance with the accessmethod designated with the character string or image data. A “button”has three types of image data that represent a normal state, a selectionstate, and a pressed state for a “link”. When the user designates onebutton image, the image data is changed in accordance with the statethat he or she has operated so that he or she can easily recognize thecurrent state of the button.

When the user designates a “link” or a “button”, he or she moves acursor on the screen with the mouse and clicks a mouse button (pressesthe mouse button several times) on a character string or an image on the“link” or an image on a “button”. The same operation can be performedwith another pointing device other than the mouse. Alternatively, with aremote control commander or a key operation of a keyboard, the user candesignate a “link” or a “button”. At that point, the user selects his orher desired “link” or “button” with a predetermined key such as adirection key and designates the selected “link” or “button” with an OKkey or the like.

In the example shown in FIG. 20, a title 61 as image data is displayedat an upper portion of the menu screen 60 that is displayed on thegraphics plane 12. The title 61 is followed by selection items 62A, 62B,62C, and 62D as links. When the user selects and designates one of theselection items 62A, 62B, 62C, and 62D with a key operation of forexample the remote control commander, a file linked to the designatedselection item is accessed.

AT lower positions of the menu screen 60, buttons 64 and 65 aredisplayed. With the buttons 64 and 65, subtitles can be displayed and alanguage of output sound can be selected from for example English andJapanese. When the buttons 64 and 65 are operated in the foregoingmanner, files used to display their setup screens are accessed and thepredetermined screens are displayed.

At a lower left portion of the menu screen 60, a character string 63that describes a method for selecting an item is displayed. Thecharacter string 63 is displayed on the graphics plane 12.

To display the menu screen as shown in FIG. 20, any descriptive languagefor describing a screen display method, link information, and so forthis required. According to the embodiment of the present invention, asthe descriptive language, used are original display control commands forsubtitles and buttons added to a command system of which DVD videonavigation commands are changed so that a menu screen for a blu-ray disccan be displayed.

On the menu screen 60 for the foregoing blu-ray disc, a table of forexample play lists is displayed with image data, a character string,buttons, and so forth. It is expected that when a particular play listis designated, the designated play list is read and reproduced from thedisc.

In the example shown in FIG. 20, a table of play lists is displayed onthe menu screen 60. In reality, images and sound of the menu screen 60and those that are generated in accordance with an item selected on themenu screen 60 are composed of a plurality of play lists. When aplurality of play lists that compose one menu item are correlated, amechanism of which a story is branched can be accomplished. When a storyis branched, a multiple story function that causes the contents of thestory to vary in accordance with the user's selection, an automaticlanguage reproducing function that causes a proper language to beautomatically reproduced in accordance with a designated language of theplayer, and a parental function that causes scenes to be changed inaccordance with the age of the user can be accomplished.

Although those functions are especially effective for recoded discs, butthey are not prescribed in the current blu-ray disc standard, whichmainly aims to record/reproduce television broadcasts.

In the following description, the structure of which a plurality of playlists are arranged is referred to as scenario. FIG. 21 shows an exampleof an internal structure of a scenario 70. The scenario 70 has aplurality of play lists 73A to 73M. In addition, the scenario 70 has twoportions (screens 80A and 80B) on which branch selection screens aredisplayed with the graphics plane 12. The screen 80A has graphics data74A and a play list 73C with which a branch selection screen isdisplayed. Likewise, the screen 80B has a graphics data 74B and a playlist 73J with which a branch selection screen is displayed.

A scenario designates both an arrangement of play lists and displaytiming at which they are displayed on the graphics plane 12. The displaytiming of the play lists on the graphics plane 12 can be designated withdisplay control commands added to an image displayed on the graphicsplane.

In the example shown in FIG. 21, the menu screen 60 corresponds to thescreen 80A of the scenario 70. A selection item (for example, theselection item 62A) on the menu screen 60 is composed of graphics 74A.When the selection item 62A is designated on the menu screen 60, theplay list 73D that corresponds to the selection item is reproduced.

In the scenario 70 shown in FIG. 21, when a disc is loaded into theplayer, the play list 73A is reproduced. After the play list 73A hasbeen reproduced, the play list 73B is reproduced. After the play list73B has been reproduced, the play list 73C is reproduced. As a result,the graphics data 74A is read and the screen 80A that prompts the userto select a branch of the story is displayed.

After the screen 80A is displayed, the story is branched in accordancewith a user's selection. In the example shown in FIG. 20, when a firstselection is performed, the screen 80A is displayed. Thereafter, theplay lists 73D, 73E, and 73F are reproduced in succession. As a result,the reproduction of the scenario 70 is completed. After the play list73F has been reproduced, the main menu screen (for example, theforegoing menu screen 60) may be displayed again.

When a second selection is performed on the screen 80A, after the screen80A is displayed, the play list 73G is reproduced. A mark is set in theplay list 73G at predetermined timing. When the play list 73G isreproduced, the play list 73G may be branched at the position of themark or fully reproduced in accordance with the setting of thereproducing apparatus, user's another scenario, or a selection on thebranch selection screen. When all the play list 73G is reproduced, afterthe play list 73G is reproduced, the play lists 73M and 73I arereproduced in succession. Thereafter, the play list 73J is reproduced.

When the play list 73G is branched at the position of the mark, the playlists 73K and 73L are reproduced in succession. After the play list 73Lhas been reproduced, the reproduction is resumed from the position ofthe mark that has been set in the play list 73I.

In the play list 73J, the graphics data 72B is read. The screen 80B thatprompts the user to select a branch of the story is displayed. In thefirst selection on the screen 80B, the play list 73F is reproduced. Inthe second selection of the screen 80B, the play list 73K is reproducedfrom the position of the mark that has been set in the play list 73K.

When a scenario is reproduced, operations corresponding to a detectedmark, a user's input, and player's operation change are performed inaccordance with command sequences (programs) executed by the player forplay lists.

Even if any of the play lists 73A to 73M is being reproduced, when amenu button of the remote control commander is pressed, the menu screen60 for a table of scenarios is displayed. An operation for a reproducingprocess for a play list for the menu screen 60 will be described. Inthis case, an event handler that corresponds to an event that takesplace when the menu button of the remote control commander is pressed(menu button press event) and that is a command that causes a play listfor the menu screen 60 to be processed is described as global eventhandler 71.

One scenario is defined in a directory. One scenario is composed of oneor a plurality of play lists. The directory is for example the foregoingBDAV directory of the standard for recording and reproducing data andthe HDMV directory (the details will be described later) supposed as thedata region only for reproduction according to the embodiment of thepresent invention.

Categories of scenarios will be described with reference to FIG. 22,FIG. 23A, FIG. 23B, and FIG. 23C. Based on connections of play lists,structures of scenarios can be largely categorized as three types thatare (1) single play list, (2) sequential play list, and (3) multipleplay list as shown in FIG. 22.

The single play list, categorized as (1), is a scenario composed of oneplay list as shown in FIG. 23A. For the single play list, a time linecan be defined. There is no interrupt during reproduction of thescenario. When the content of the single play list is a movie, after thedisc is loaded, only a movie main part is reproduced.

The sequential play list, categorized as (2), is a scenario composed ofa plurality of play lists that are linearly arranged without a branch asshown in FIG. 23B. The play lists are arranged in such a manner that theend of one play list is connected to the beginning of the next playlist. In the sequential play list, a time line can be defined for eachplay list. When the content of the sequential play list is a movie, thescenario is composed of a menu screen and a movie main part. After thedisc is loaded, a play list that causes a menu screen to be displayed isexecuted. When the reproduction of the movie main part is designated onthe menu screen, the next play list is executed and the movie main partis reproduced.

The multiple play list, categorized as (3), is a scenario that has abranch of a play list and a connection of play lists as shown in FIG.23C. In the multiple play list, a time line cannot be defined throughall play lists. Instead, a time line is defined in each play list. Withthe multiple play list, an interactive function and a game function forvarying reproduction contents in accordance with a user's input can beaccomplished. When the content of the multiple play list is a movie, amultiple angle function that allows the user to select a desired anglefrom various angles photographed for the same scene can be accomplished.

In the reproduction-only medium, one scenario is defined for the HDMVdirectory. However, it is necessary to allow the user to recognize thescenario in smaller units. Nevertheless, the unit of a play list doesnot always accord with a unit that the user can recognize. When one playlist describes three movies, it is necessary to allow the user to see asearch point of each movie. A search point (entry point) that isindependent from the structure of a play list is referred to as titleand/or chapter.

Next, with reference to FIG. 24, titles and chapters will be described.A title represents any reproduction start point in a scenario. In theexample shown in FIG. 24, a title 1 is placed at the beginning of a playlist 470A. A title 2 is placed in the middle of a play list 470D. Aregion after the beginning of the play list 470A until the title 2 isthe title 1. A chapter is a unit of which a title is sub-divided. Thecan also recognize a chapter as a reproduction start point. The title 1is sub-divided into chapters. In the example shown in FIG. 24, the title1 has chapters 1, 2, and 3. Thus, the title 1 is sub-divided into threeportions. As shown in FIG. 24, each of a title and a chapter can beplaced in the middle of a play list.

Next, a model of a reproducing apparatus that operates in accordancewith description of a scenario will be considered. The modeledreproducing apparatus is referred to as BD (Blu-ray disc) virtualplayer. The definition of the structure of the BD virtual player isreferred to as BD virtual player model.

Next, with reference to FIG. 25, the BD virtual player model will bedescribed. After a disc is loaded into a BD virtual player 30, it readsas a PBC program 40 a scenario described in the scenario descriptivelanguage defined in the present invention from the disc and operates inaccordance with the description of the scenario.

The BD virtual player 30 reproduces data from a disc shaped recordingmedium defined according to the embodiment of the present invention. TheBD virtual player 30 is an object in a computer environment such as apersonal computer. The computer environment is not limited to ageneral-purpose personal computer. Instead, the computer environmentincludes a software environment incorporated with a dedicatedreproducing apparatus and/or recording and reproducing apparatus thatreproduces data from a disc shaped recording medium defined according tothe embodiment of the present invention. Hereinafter, a disc shapedrecording medium defined according to the embodiment of the presentinvention is referred to as disc.

The BD virtual player 30 roughly has two states A and B. In the state A,the BD virtual player 30 reproduces a play list and graphics. In thestate B, the BD virtual player 30 stops reproducing a play list andgraphics. A state change from one state to another state and adesignation of the next operation in one state are performed by commandsto an object of the BD virtual player 30.

The state A has a plurality of operations. As operations in the state A,there would be a high speed reproduction, a variable speed reproductionsuch as a reverse reproduction, and a special reproduction such as ajumping reproduction that starts from any time of a disc. When data ofthe graphics plane 12 is displayed, the variable speed reproduction andthe special reproduction of the BD virtual player 30 would berestricted.

A PBC (Play Back Control) program 40 corresponds to a scenario recordedon the disc. As will be described later, a scenario describes areproducing method for a play list recorded on the disc and a displayingmethod for a menu screen. The PBC program 40 and the BD virtual player30 exchange commands through an API (Application Programming Interface)41 so as to reproduce a play list recorded on the disc.

A scenario has two regions for commands including a program havingcommands that cause the player to be operated. The two regions arereferred to as global command region and local global command region.

The global command region has programs that are effective for the entirescenario. For example, the global program region describes a programthat causes the player to initialize parameters when a disc is loadedinto the player and to jump to a play list that composes a menu screen.The local command region describes programs for play lists. Localcommands are categorized as four types of commands that arepre-commands, play item commands, post commands, and button commands.

FIG. 26A and FIG. 26B show an outlined operation of the BD virtualplayer 30 with a scenario that describes original commands as adescriptive language according to the embodiment of the presentinvention. FIG. 26A shows an example of a disc loading operation of theBD virtual player 30. As described above, one scenario is created forthe BDMV directory that will be described later. When the disc is loadedinto the player and then an initial access is performed for the disc (atstep S30), registers, namely, the common parameters 32 are initialized(at step S31). At the next step S32, a program is read from the disc andexecuted. The initial access represents an operation of whichreproduction for a disc is performed first time for example when a discis loaded into the player.

A command group (a program) that is initially read and executed when thedisc is loaded into the player is referred to as global commands. Theglobal commands describe for example an advertisement picture (trailer)and a jump command that jumps to a play list that composes a menuscreen. The player reproduces the play list in accordance with thecommands.

FIG. 26B shows an example of an operation of the player 30 when the userpresses for example the play key while the player is in the stop state.This operation corresponds to the state change from the state B to thestate A of the BD virtual player 30 as described in FIG. 25. In the stopstate (at step S40), the user causes the BD virtual player 30 to operatein the reproduction mode with for example the remote controller (UOP:User Operation). At a result, the registers (namely, the commonparameters 32) are initialized (at step S41). At the next step S42, theBD virtual player 30 enters a play list reproduction phase.

Next, with reference to FIG. 27A and FIG. 27B, reproduction of a playlist in the play list reproduction phase will be described. FIG. 27Ashows an example of which a play list is composed of a single play item.A play list has a pre-command region, a play item command region, and apost-command region that describes respective programs. In the play listreproduction phase, a pre-command of the pre-command region is executed(at step S10). After the pre-command has been executed, the playerenters a play item reproduction phase for play items that compose theplay list (at step S11). In the play item reproduction phase, a streamwhose start point and end point are designated by a play item isreproduced (at step S110). When the stream has been reproduced up to theend point, the play item command is executed (at step S111). After theplay item command has been executed, a post command of the post-commandregion is executed (at step S12). As a result, the play list has beenreproduced.

The post command is normally a jump command that describes as a jumpcommand a play list to be reproduced next or a play list that composes amenu screen. When there is no a jump command, the player enters the stopstate (the state B shown in FIG. 25B).

FIG. 27B shows an example of which a play list describes a plurality ofplay items. In this case, the play list has a pre-command region, a playitem command region, and a post-command region that describe respectivecommands. When the play list describes a plurality of play items, theplay item command region describes play item streams and play itemcommands of play items arranged in a time sequence.

When the play list describes a plurality of play items, in the play listreproduction phase, a pre-command is executed (at step S10). In the nextplay item reproduction phase, a stream is reproduced from the startpoint to the end point of each play item and a play item command isexecuted for each play item. In the example shown in FIG. 27B, a firstplay item stream is reproduced (at step S110-1). Thereafter, thecorresponding play item command is executed (at step S111-1).Thereafter, a second play item stream (not shown) is reproduced (at stepS110-2). The corresponding play item command is executed (at stepS111-2). These operations are repeated for the number of the play items.After the last play item stream has been reproduced (at step S110-n) andthe corresponding play item command has been executed (at step S111-n),the play item reproduction phase is completed. After the play itemreproduction phase has been completed, a post command is executed (atstep S12). As a result, the play list reproduction phase is completed.

FIG. 28A, FIG. 28B, FIG. 28C, FIG. 28D, FIG. 28E, FIG. 28F, FIG. 28G,and FIG. 28H show part of commands. When commands exemplified in FIG.28A, FIG. 28B, FIG. 28C, FIG. 28D, FIG. 28E, FIG. 28F, FIG. 28G, andFIG. 28H are described in the post command region and a button commandregion that will be described later, a jump to a predetermined play listcan be accomplished. Besides these commands shown in FIG. 28A, FIG. 28B,FIG. 28C, FIG. 28D, FIG. 28E, FIG. 28F, FIG. 28G, and FIG. 28H, othercommands can be defined.

Next, commands for designating a reproduction start position will bedescribed. A command LinkPlayList (playListNumber) causes thereproduction of a play list designated by “playListNumber” to bestarted. A command LinkPlayItem (playListNumber, playItemNumber) causesthe reproduction of a designated play item of a designated play list tobe started. “playItemNumber” is “PlayItem_id” whose value starts from“0”. When “playItemNumber” is designated a value “0”, a play list towhich the play item belong is reproduced from the beginning.

A command Link (position) (object) causes the current position to bemoved in a scenario. This command causes the current position to bemoved to the adjacent play list, play item, or chapter. A parameter“position” is one of “prev”, “next”, “top”, “Parent”, or “tail”. Aparameter “object” describes a moving method for an object (a play list,a play item, or a chapter) represented by the parameter “object”.

A command Exit causes the reproduction of a scenario to be stopped. Inthis case, the value of the standard register is not held. A command RSMcauses resume information stored in the memory of the player to becalled, set to a register, and the reproduction of the scenario to bestarted.

Next, commands for obtaining the state of the player will be described.A command getMenuDescriptionLanguage( ) causes a language used todisplay a menu to be obtained. A command getScenarioNumber( ), a commandgetPlayListNumber( ), and a command getChapterNumber( ) cause a scenarionumber, a play list number, and a chapter number that are beingreproduced, respectively, to be obtained. A command getPlayerSupport( )causes version information of the player to be obtained.

Next, commands for video streams will be described. A commandgetVideoStreamAvailability( ) causes information that describes whetheror not a designated video stream to be contained. A commandsetVideoStreamNumber( ) describes a video stream to be decoded. Acommand getVideoStreamNumber( ) causes the number of a video stream thatis being selected to be obtained. Attributes of a video stream are forexample an encoding system, a resolution, an aspect ratio, a displaymode in the case that the aspect ratio is 4:3, and presence/absence ofclosed caption. A command setAngleNumber( ) describes an angle number. Acommand getAngleNumber( ) causes an angle number that is being selectedto be obtained. A command getMaxVideoStreams( ) causes a maximum numberof bit streams to be obtained.

Next, according to the embodiment of the present invention, a method forrecording commands and databases that describe a scenario to a disc willbe described. FIG. 29 shows an example of a file management structureaccording to the embodiment of the present invention. On the disc, oneroot directory is created. A portion under the root directory is managedby one reproducing system.

Under the root directory, a directory BDMV is placed. Although it is notshown, similar to FIG. 4 described above, a plurality of directoriesBDMV can be placed under the root directory. Hereinafter, a systemdefined by the embodiment of the present invention is referred to asBDMV.

Under the directory BDMV, two files “scenario.hdmv” and “entrylist.data”are placed. In addition, a plurality of directories “PLAYLIST”,“CLIPINF”, and “STREAM” are placed.

FIG. 30 shows a syntax that describes an example of a structure of thefile “scenario.hdmv”. The file “scenario.hdmv” is a file that isinitially read and executed when an initial access is performed (namely,when the disc is loaded). The file “scenario.hdmv” has a fileidentification code (a field type_indicator) and a version number (afield version_number). The version number is followed by functional datablocks.

The field type_indicator has a data length of 32 bits. The fieldtype_indicator has a predetermined character string that describes thatthe file is “scenario.hdmv”. The field version_number has a data lengthof 32 bits for a version number. A field Scenario_start_address has adata length of 32 bits for an unsigned integer of a value thatrepresents the position of the block Scenario( ) with the relativenumber of bytes from the beginning of the file “scenario.hdmv”.

A block Autoplay( ) starts from the 41-st byte (fixed position) of thefile. The block Autoplay( ) describes a program that is executed whenthe initial access is performed (reproduction for the disc is initiallyperformed for example the disc is loaded). The block Autoplay( ) has theforegoing global commands described above. The block Autoplay( ) isfollowed by any number of padding words (padding_word) that allow aspace to be formed after the block.

FIG. 31 shows a syntax that describes an example of a structure of theblock Autoplay( ) shown in FIG. 30. A field length has a data length of32 bits for an unsigned integer. The field length describes the datalength immediately after the end of the field length until the end ofthe block Autoplay( ) in bytes. A field number_of commands describes thenumber of fields command(i) preceded thereby. The field command(i) has adata length of 32 bits as shown in FIG. 28A, FIG. 28B, FIG. 28C, FIG.28D, FIG. 28E, FIG. 28F, FIG. 28G, and FIG. 28H. The field command(i)describes a set of parameters of the player and commands such as areproduction start command for a designated play list and a calculationcommand.

A block Scenario( ) describes a “scenario” as explained above. The blockScenario( ) describes information about the reproduction order of playlists and a local command region for each play list.

FIG. 32 shows a syntax that describes an example of a structure of theblock Scenario( ). The block Scenario( ) is a block that definesinformation of a scenario, namely links among play lists. The blockScenario( ) describes information about the foregoing pre-commands,post-commands, and play item commands and these commands themselves. Theblock Scenario( ) has a region for fields of information about commandsdescribed therein and a region for those pre-commands, post-commands,and play item commands.

A field length describes a value that represents the length immediatelyafter the end of the field length to the end of the block Scenario( ) inbytes. A field number_of_PlayLists describes the number of play liststhat composes the scenario. The field number_of_PlayLists is followed bydata of each play list. Data for each play list is repeated the numberof times designated by a loop counter i in a for loop, the maximum valueof i being represented by the field number_of_PlayLists.

A field Pre_Command_start_id describes a start number of a pre-commandin a command table (a pre-command is executed before a play list isreproduced). A number described in the field Pre_Command_start_iddescribes a loop counter j in a for loop that describes a fieldPl_Command(i) that will be described later. Likewise, a fieldPost_Command_start_id describes a start number of a post command in thecommand table (a post command is executed after a play list isreproduced). A number described in the field Post_Command_start_iddescribes the loop counter j in the for loop that describes the fieldPL_Command A) that will be described later.

A field Number_of_Pre_Commands describes the number of pre-commands thatcompose a program. Pre-commands are executed before a play list isreproduced. Likewise, a field number_of Post_Commands describes thenumber of post-commands that composes a program. Post commands areexecuted after a play list has been reproduced. These programs aredescribed in a command table that will be described later.

A field number_of PlayItems describes the number of play items thatcomposes the play item. A field PI_Command_start_id represents a startnumber of a play item command in a command table. A play item command isexecuted after the play item has been reproduced. A number described inthe field PI_Command_start_id describes a loop counter j in a commandtable that will be described later. A field number_of_PI_Commandsdescribes the number of play item commands, which are executed after theplay item has been reproduced. Commands after the position described inthe field PI_Command_start_id until the number of commands described inthe field number_of_PI_Commands are executed after the play item hasbeen reproduced.

A field number_of_PL_Commands describes the number of commands in acommand table preceded by the field number_of_PL_Commands. The commandtable has a for loop that describes a field PL_Command (j). Commands inthe command table are assigned number j. The number j corresponds to theloop counter j in the for loop that describes the command table. A fieldPL_Command (j) describes one command. The number j is referenced fromthe foregoing field Pre_Command_start_id, the fieldPost_Command_start_id, and the field PI_Command_start_id.

FIG. 33 shows a syntax that describes an example of a data structure ofthe file “entrylist.data”. The file “entrylist.data” describes a fileidentification code (a field type_indicator), a version number (a fieldversion_number), and a block start address (a fieldScenarioEntry_start_address). The block start address is followed byfunctional data blocks.

The field type_indicator has a data length of 32 bits for apredetermined character string that describes entry points of a titleand a menu. A field version_number has a data length of 32 bits for aversion number. The field ScenarioEntry_start_address has a data lengthof 32 bits for an unsigned integer value that describes the startposition of the block ScenarioEntry( ) with the relative number of bytesfrom the beginning of the field “entrylist.data”.

FIG. 34 shows a syntax that describes an example of a structure of ablock AppInfo( ). A field length has a data length of 32 bits for anunsigned integer that describes the length immediately after the end ofthe field length until the end of the block AppInfo( ) in bytes. A fieldHDMV_name_character_set describes a character set for a field HDMV_namethat will be described later. A field PIN_valid_flag describes whetheror not a personal identification number should be set when reproductionis performed. When the setting is valid, a field PIN that is followed bythe field PIN_valid_flag describes a personal identification number. Afield HDMV_name_length describes the length of a valid portion of afield HDMV_name that is preceded by the field HDMV_name_length. Thefield HDMV_name is a region that describes a name of the directory HDMVin which the file “entrylist.data” is placed. The name of the directoryHDMV is described in the text format. The field HDMV_name has a fixeddata length of 255 bytes. The name of the directory HDMV is describedfor a length described in the field HDMV_name_length after the beginningof the field HDMV_name.

FIG. 35 shows a syntax that describes an example of a structure of theblock ScenarioEntry( ). The block ScenarioEntry( ) describes searchpoints of a scenario. As described above, one scenario is created forthe directory HDMV. A scenario links a plurality of play lists placedunder the directory HDMV so as to define the reproduction order of theplay lists. When the user sees a scenario, it does not always look likeone picture unit or one sound unit, but as if it were composed of aplurality of “titles”.

When three movies are recorded on one disc, only one scenario thatdefines the reproduction order of the movies exists on the disc.However, the user would see them as if three titles were recorded on thedisc. Alternatively, a list of three titles would be displayed.Including a title menu that allows the user to select one of the titles,he or she would see them as if four titles were recoded. Since the userconsiders a menu screen as one picture unit or one sound unit, accordingto the embodiment of the present invention, a menu screen is treated asone type of a title.

Since the unit of a scenario that defines a link of play lists isdifferent from the unit that the user recognizes data as picture andaudio, as described above, it is necessary to define search points in ascenario. A search point in a scenario is referred to as title entry.The block ScenarioEntry( ) describes information of a title entry.

Returning to FIG. 35, a field length has a data length of 32 bits for anunsigned integer that describes the length immediately after the fieldlength until the end of the block ScenarioEntry( ) in bytes. A fieldname_character_set describes a character set of a field TopMenu_name anda field Title_name that are preceded by the field name_character_set.

The next block Top menu PL( ) describes an entry point to a play list ora play list group that composes a menu displayed when the user pressesthe title menu key of the remote controller. One scenario has one topmenu. The top menu is used to present for example titles to the user. Asub menu on which the user can set audio and subtitles can be placed asa lower menus of the top menu. A sub menu is also referred to as streamsetup menu.

In short, a field flags is a region that describes attribute informationof a top menu. A field TopMenu_ref_to_PlayList_file_name describes aplay list that composes a top menu or a play list that is an entry to aplay list group. A field TopMenu_ref_to_PlayItem_id describes the numberof a play item from which the top menu starts in a play list describedin the field TopMenu_ref_to_PlayList_file_name. When the play list isreproduced from the beginning, the value of the fieldTopMenu_ref_to_PlayItem_id is “0”. A field TopMenu_name_lengthrepresents the length of the name assigned to a top menu. A fieldTopMenu_name describes a character string of the name assigned to a topmenu.

The block Top Menu PL( ) describes information about a title. A fieldnumber_of_Titles describes the number of title search points (titleentries) in a for loop immediately preceded by the fieldnumber_of_Titles. In short, a field flags is a region that describesattribute information about a title. A fieldTitle_ref_to_PlayList_file_name describes the file name of a play listthat includes a title entry. A field Title_ref_to_PlayItem_id is usedwhen a title starts from a particular play item of a play list describedin the field Title_ref_to_PlayList_file_name. A field Title_name_lengthdescribes the length of the name assigned to a title. A field Title_namedescribes a character string of the name assigned to a title.

Next, information about a sub menu is described. “Stream Setup Menu” isfollowed by an entry point to a play list or a play list group thatcomposes a stream setup menu (namely, a sub menu) for each play item. Astream setup menu can be used for each play list to select such assound, subtitles, or angle. For example, when the buttons 64 and 65shown in FIG. 20 are pressed, a sub menu is displayed as a screen.

A field number of PlayLists describes the number of play lists used fora stream setup menu. The value of the field number_of_PlayLists is usedas the number of loop times of a for loop immediately preceded by thefield number_of_PlayLists. In short, a field SSMenu_flags is a regionthat describes attribute information about a stream setup menu. A fieldSSMenu_ref_to_PlayList_file_name describes a play list that composes astream setup menu or a play list that is an entry of a play list group.A field SSMenu_ref_to_PlayItem_id describes the number of a play itemfrom which a stream setup menu starts in a play list described in thefield SSMenu_ref_to_PlayList_file_name. When a play list is reproducedfrom the beginning, the value of the field SSMenu_ref_to_PlayItem_id is“0”.

FIG. 36 shows a syntax that describes an example of a structure of afile “xxxxx.mpls”. In FIG. 36, the file “xxxxx.mpls” has functionalblocks of information. A field type_indicator describes a characterstring of the file. A field version_number describes the version of thefile. Fields PlayList_start_address and PlayListMark_start_addressdescribe the start addresses of corresponding blocks as addressinformation having a data length of 32 bits.

A block PLControlInfo( ) describes attribute information about the playlist. A block PlayList( ) describes information about a play item thatcomposes the play list. A block PlayListMark( ) describes information ofa mark added to the play list.

In the file “xxxxx.mpls”, since start addresses of the blockPLControlInfo( ), PlayList( ), and PlayListMark( ) are followed by theseblocks, padding data padding_word can be placed before and/or after eachblock in a desired length. The start position of the first blockPLControlInfo( ) is fixed at the 41-st byte from the beginning of thefile.

FIG. 37 shows a syntax that describes an example of a structure of theblock PLControlInfo( ). The block PLControlInfo( ) describes varioustypes of attribute information about a play list, not directly requiredto reproduce the play list. A field PlayList_character_set describes acharacter set of character string information about a play list.

A field PL_playback_type describes a value as shown in FIG. 38. Thefield PL_playback_type describes whether the play list is a regular playlist that is sequentially reproduced, a play list of which play itemsare reproduced at random, or a play list of which play items areshuffled and reproduced. The random shuffle is designated in the unit ofa play list. One play list should not describe a regularly reproducedplay item and a randomly shuffled play item block. When the disc is areproduction-only recording medium, the producer may designate a randomreproduction or a shuffle reproduction. At that point, such informationis required.

A field playback_count describes the number of times of reproduction ofa play item when the play list is a random reproduction play list or ashuffle reproduction play list. A field playback_count describes thenumber of play items that are randomly reproduced or shuffle-reproduced.

A field PL_UOP_mask_table( ) describes information about restriction ofuser's operations. When the user is prohibited from performingoperations such as playback, fast forward, fast rewind, and so forthwhile a play list is being reproduced, this region is properlydescribed. When a proper value is described in the fieldPL_UOP_mask_table( ), an alarm notice, a copyright notice, and so forthcan be prevented from being skipped even if a fast forward operation orthe like is performed.

A field PL_random_access_mode describes a value as shown in FIG. 39. Thefield PL_random_access_mode describes whether a random access of whichany position of the play list is jump-reproduced can be performed. Whenthere is a play list that the disc producer wants the user to see, thevalue of the field PL_random_access_mode is set to [0x1]. When this playlist is jump-reproduced, fast forward operation, fast rewind operation,reproduction from any time, and so forth are prohibited. When the discis a reproduction-only recording medium, scenes such as a logo of acontents production company and precautions to be seen to the user maybe recorded thereon. The field PL_random_access_mode describesinformation necessary for prohibiting such scenes from being skippedagainst variable speed reproduction operation or the like.

A field PlayList_duration describes a reproduction duration of a playlist. A field PlayList_name describes a play list name having aneffective length with a value described in the fieldPlayList_name_length. A field PlayList_detail describes detailedinformation about a play list having an effective length with a valuedescribed in the field PlayList_detail_length.

FIG. 40 shows a syntax that describes an example of a structure of ablock PlayList( ). A field length describes a byte length immediatelyafter the field length until the end of the block PlayList( ). A fieldnumber_of_PlayItems describes the number of play items that compose theplay list. A field number_of_SubPlayItems describes the number ofauxiliary play items (sub play items) reproduced along with the mainplay item.

A block PlayItem( ) describes information of a play item. A blockSubPlayItem( ) describes information of a sub play item.

FIG. 41 shows a syntax that describes an example of a structure of theblock PlayItem( ). A field Clip_Information_file_name describes acharacter string of a file name of a clip information file (that has anextension of “clpi”) corresponding to a clip that play item referencesin the relation of 1 to 1.

A field Clip_codec_identifier describes an encoding system of a clipreferenced by the play item. According to the embodiment, the fieldClip_codec_Identifier describes a fixed value “M2TS2”. In other words,according to the embodiment, the encoding system of a clip referenced bya play item is fixed to a system represented by the value “M2TS”.

A flag is_multi_angle describes whether or not the play item has amultiple angle structure (a first flag).

A field connection_condition is information that describes in whatmanner the play item and the next play item are connected. The fieldconnection_condition describes whether or not play items can beseamlessly reproduced.

A field ref_to_STC_id describes a sequence STC_sequence in a clipreferenced by the play item. The sequence STC_sequence has a uniquestructure of the blu-ray disc standard that describes that PCR (ProgramClock Reference) as a reference of the time base of an MPEG2 TS(Transport Stream) represents a continuous range. The sequenceSTC_sequence describes a number STC_id that is unique in the clip. Sincea continuous time base can be defined in the sequence STC_sequence, thestart time and the end time of a play item can be uniquely designated.In other words, the start point and the end point of each play itemshould be present in the same sequence STC_sequence. A fieldref_to_STC_id describes a sequence STC_sequence with a number STC_id.

Fields IN_time and OUT_Time describe time stamps pts(presentation_time_stamp) of the start point and the end point of theplay item in the sequence STC_sequence, respectively.

A field PI_UOP_mask_table( ) describes data about a restriction againstuser's operations. Even if the user performs such a restrictedoperation, the player should not respond to that. To restrict a fastforward operation while a menu screen is being displayed, data about arestriction against such an operation is described in the fieldPI_UOP_mask_table( ).

The field PI_UOP_mask_table( ) is described for each play item. Thefield PI_UOP_mask_table( ) describes information that has the sameobject as the field PL_UOP_mask_table( ) of the foregoing blockPLControlInfo( ), which describes information about reproduction of aplay list. A user's operation can be prohibited in either a play list ora play item. A user's operation during reproduction of a play item isprohibited depending on the result of an OR operation of information ofa play list and information of a play item.

In short, a field PID_filter( ) is a table that describes the priorityin streams reproduced by play items.

A field PI_random_access_mode describes a value as shown in FIG. 42. Thefield PI_random_access_mode describes whether or not a random access canbe performed for jump-reproduction of any position of a play item. Whenthere is a play list that the disc producer side wants the user to see,a value [0x1] is described in the field PI_random_access_mode. Thus,when reproduction of a play item is started, the user can be prohibitedfrom performing a fast forward operation, a rewind operation, areproducing operation from any time, or the like.

A field still_mode describes whether or not after reproduction of a playitem is started, the reproduction is temporarily stopped. The fieldstill_mode describes a value as shown in FIG. 43. When the value of thefield still_mode is [0x1], it describes that reproduction of the playitem is temporarily stopped for a period described in the next fieldstill_time. Thus, still pictures can be successively displayed atintervals of a predetermined period like a slide show. In this case,each still picture is a play item. In addition to a setting for adesignated time period, a setting for a non-designated time period ofwhich reproduction is stopped until the user inputs data (pause setting)can be described in the field still_time. When the value of the fieldstill_mode is [0x2], the pause setting can be performed.

When the value of the foregoing flag is_multi_angle is for example “1”,the play item is a multiple angle play item. After “Angle”, informationabout multiple angles is added.

A field number_of_angles describes the number of angles. A fieldis_seamless_angle_change describes a value as shown in FIG. 44. Thefield is_seamless_angle_change describes whether or not each angel hasbeen recorded on the disc so that each angel can be seamlessly changed.

The next for loop describes information about clips that compose angles.A field Clip_Information_file_name in the for loop describes a characterstring of a field name of a clip information file (that has an extension“clpi”) that corresponds to each clip that the play item references inthe relation of 1 to 1. A field ref_to_STC_id describes a sequenceSC_sequence of each clip that the play item references.

An angle corresponding to a value angle_id=0 has been defined in thefirst half part of the block PlayItem( ) like a regular play item thatis not an angle play item. Angles after the value angle_id=1 are definedin the for loop. The for loop does not contain an angle corresponding tothe value angle=0.

FIG. 45 shows a syntax that describes an example of a structure of ablock SubPlayItem( ). A field length describes the length immediatelyafter the field length until the end of the block SubPlayItem( ) inbytes. A field Clip_Information_file_name describes a character stringof a file name of a clip information file (that has an extension “clpi”)that corresponds to a clip that the sub play item references in therelation of 1 to 1.

A field Clip_codec_identifier describes an encoding system of a clipthat the sub play item references. According to the embodiment, thefield Clip_codec_Identifier is fixed to a value “M2TS”.

A field is_repeat_flag describes a value as shown in FIG. 46. The fieldis_repeat_flag is a flag that describes whether or not the sub play itemis repeatedly reproduced not in synchronization with a main play item(main path). When the value of the field is_repeat_flag is “1”, the subplay item is repeatedly reproduced until the main play item has beenreproduced not in synchronization therewith. When the value of the fieldis_repeat_flag is “0”, the sub play item is reproduced once insynchronization with the main play item.

If the sub play item is a sub play item for only audio, when “1” isdescribed in the field is_repeat_flag, BGM (Back Ground Music) can bereproduced.

A field SubPlayItem_type describes what characteristic the sub play itemhas. For example, when the value of the field SubPlayItem_type is “1”,it describes that the sub play item is a sub play item for only audio.

A field ref_to_STC_id describes a sequence STC_sequence of a clip thatthe play item references. Fields SubPlayItem_IN_time andSubPlayItem_OUT_Time describe time stamps pts (presentation_time_stamp)of the start point and end point of the sub play item in the sequenceSTC_sequence.

When the value of the foregoing field is_repeat_flag is “0” and itrepresents that the sub play item is reproduced in synchronization withthe main play item, the field sync_PlayItem_id and the fieldsync_start_PTS_of_PlayItem describe from what time of the main play itemthe sub play item is reproduced in synchronization therewith.

As shown in FIG. 47, the field sync_PlayItem_id describes a play item ofa main path (PlayItem=1). The field sync_start_PTS_of_PlayItem describestime of the main play item at which reproduction of a sub play item isstarted (t1). A field SubPlayItem_IN_time and a fieldSubPlayItem_OUT_time describe a period for which a click as a sub playitem is reproduced.

FIG. 48 shows a syntax that describes an example of a structure of thefile “zzzzz.clpi”. In FIG. 48, the file “zzzzz.clpi” has functionalblocks of information. A field typeindicator describes a characterstring of the file. A field version_number describes the version of thefile. A field SequenceInfo_start_address, a fieldProgramInfo_start_address, a field CPI_start_address, and a fieldClipMark_start_address describe start positions of respective blocks.

FIG. 49 shows a syntax that describes an example of a structure of ablock ClipInfo( ). A field length describes the length immediately afterthe field length until the end of the block ClipInfo( ). A fieldClip_stream_type describes the type of a clip AV stream. The value ofthe field Clip_stream_type may be fixed to for example “1” thatrepresents a normal clip in the reproduction-only disc standard.

A field application_type describes how a clip AV stream (that has anextension “m2ts”) has been multiplexed. The field application_typedescribes a value as shown in FIG. 50. The field application_typedescribes whether the clip AV stream is a normal video stream or astream that has been multiplexed suitably for a still picture.

More practically, in the example, the value of the fieldapplication_type is “1” and it describes that the file of thecorresponding clip AV stream complies with the rule of the HDMVtransport stream according to the embodiment. With the clip AV stream, anormal moving picture is reproduced.

When the value of the field application_type is “2”, it describes thatthe file of the corresponding clip AV stream complies with the rule ofthe HDMV transport stream for a still picture that synchronizes with thereproduction of audio. The clip AV stream is a file in accordance withfor example the MPEG2 format. In the clip AV stream, video data andaudio data have been multiplexed. The video data has a structure ofwhich I pictures of the MPEG2 are arranged as still pictures. As aresult, the still pictures can be reproduced like a slide show on thetime base of audio. This reproduction is referred to as time base slideshow.

When the value of the field application_type is “3”, it describes thatthe file of the corresponding clip AV stream complies with the rule ofthe HDMV transport stream for still pictures reproduced not insynchronization with audio. The audio data and the video data arestructured as different files. While the audio data is being reproduced,the video data is displayed in such a manner that still pictures arechanged at any intervals or as designated by the user. The video datacan be structured in such a manner that for example I pictures of theMPEG2 are arranged as still pictures. Such reproduction is referred toas browsable slide show.

When the value of the field application_type is “0”, the correspondingclip AV stream does not comply with the rule of the HDMV transportstream.

It is assumed that multiplexing suitable for displaying still picturesallows an application such as a slide show of still pictures to beeasily accomplished. In such an application, when one still picture iscapsulate-multiplexed with subtitles and graphics data to besuperimposed, they can be easily read.

When a still picture is multiplexed with subtitles and graphics in thesame manner as a normal moving picture, subtitles to be displayed alongwith a still picture are multiplexed with picture data of a precedingstill picture (namely, so-called multiplexing phase difference takesplace). As a result, unless stream data is read for a long time, a stillpicture superimposed with subtitles and graphics cannot be displayed.

According to the embodiment of the present invention, graphics data forvideo data and subtitles is contained in TS (Transport Stream) packetsof the MPEG. One TS packet is composed of 188 bytes. The foregoing videodata and graphics data are divided so that they are contained in TSpackets. When a packet of subtitle data corresponding to particularstill picture data (called picture P1) is preceded by a packet of thenext still picture (called picture P2), to display subtitlescorresponding to the picture P1, data of the picture P2 should have beenread.

When a particular still picture is multiplexed with only associatedsubtitles and graphics (capsulated), a stream that is not affected byother data can be created. When such an operation is repeated for eachstill picture and streams are connected, one stream of which data ofeach still picture (and associated subtitles and graphics data) isconnected in series can be obtained. The stream that has beenmultiplexed in such a manner is referred to as still picture HDMVstream.

There are two types of HDMV streams for still pictures that are timebase slide show and browsable slide show. According to the embodiment,the two types are distinguished with different numbers of the fieldapplication_type.

When a still picture and associated subtitles and graphics arecapsulated and recorded, accessibility of which still pictures arechanged and reproduced is improved.

Returning to FIG. 49, a field Clip_stream_type describes the type of aclip AV stream. A field num_of_source_packets describes the number ofpackets contained in a clip AV stream. A field BD_system_use and a blockTS_type_info_block( ) do not relate to the present invention. Thesedescription will be omitted.

FIG. 51 shows a syntax that describes an example of a structure of ablock SequenceInfo( ). A field length describes the length immediatelyafter the field length until the end of the block SequenceInfo( ) inbytes. A field num_of_ATC_sequence describes the number of sequencesATC_sequence that have been recorded in a continuous time period. When areproduction-only medium is used, since the number of sequencesATC_sequence is “1”, the description of the field num_of_ATC_sequenceswill be omitted. A field SPN_ATC_start describes the beginning of thesequence ATC_sequence with a packet number. When the number of sequencesATC_sequence is “1”, the beginning of the sequence ATC_sequence accordswith the beginning of the clip AV stream file. Thus, the value of thefield SPN_ATC_start is “0”.

A field num_of_STC_sequences describes the number of sequencesSTC_sequence of the sequence ATC_sequence. When a reproduction-onlymedium is used, since the number of sequences STC_sequence is “1”, thedescription thereof will be omitted. A field offset_STC_id describes afixed value “0”. A field PCR_PID describes a PID of a TS packet that hasa PCR (Program Clock Reference) of an MPEG2 TS. A field SPN_STC_startdescribes the beginning of a sequence STC_sequence with a packet number.When the number of sequences STC_sequence is 1, since the fieldSPN_STC_start accords with the beginning of the clip AV stream file, thevalue of the field SPN_STC_start is “0”. A field presentation_start_timeand a field presentation_end_time describe a valid range of the clip AVstream. The range described in the field presentation_start_time and thefield presentation_end_time can be referenced from a play item.

FIG. 52 shows a syntax that describes an example of a structure of ablock ProgramInfo( ). A syntax structure of a block PorgramInfo( ) for arecordable medium can be applied to that for a reproduction-only medium.Since there is no new structure in the block ProgramInfo( ), detaileddescription is omitted. In the block ProgramInfo( ), as restrictions, avalue “1” can be described in a field num_of_program_sequences and avalue “1” can be described in a field num_of_groups.

FIG. 53 shows a syntax that describes an example of a structure of ablock StreamCodingInfo( ). Like the block ProgramInfo( ), the blockStreamCodingInfo( ) has a syntax structure similar to that of therecordable medium. With respect to video data, the blockStreamCodingInfo( ) describes attribute information of a format of videodata, a frame rate, and an aspect ratio. With respect to audio data, theblock StreamCodingInfo( ) describes attribute information of a samplingfrequency and so forth. When the syntax structure of the recordablemedium is applied to the reproduction-only medium, as shown in FIG. 53,it is necessary to add a field language_code that describes a languageof subtitles and audio streams to the block StreamCodingInfo( ). Thisinformation is effective when the most suitable language for audio andsubtitles is selected in accordance with setting of the player.

FIG. 54 shows a syntax that describes an example of a structure of ablock CPI( ). Generally, in an encoded stream such as an MPEG streamthat has been compressed between frames, the stream can be decoded atlimited positions for example the beginning of a GOP (Group Of Picture).The CPI (Characteristic Point Information) is a database that is acollection of information about start positions at which data can bedecoded. The database correlates reproduction times and addresses of afile. The CPI tabulates information that describes start positions atwhich data can be decoded.

When data is reproduced from any time, by referencing the CPI as such adatabase with the reproduction time, the address of the reproductionposition in the file can be obtained. Since this address is thebeginning at which data can be decoded, the player can read datatherefrom and quickly display a picture.

A start position at which data can be decoded (in this example, thestart position of a GOP) is described in the CPI and is referred to asEP (Entry Point) entry.

A field CPI_type describes the type of CPI. The field CPI_type describesa value as shown in FIG. 55. According to the present invention, thetype of the field CPI_type describes CPI for a reproduction-only medium.In reality, the value of the field CPI_type is “8” that describes an EPentry map for HDMV (EP_map_type_for_HDMV).

FIG. 56 shows a syntax that describes an example of a data structure ofa block EP_map of an EP entry for a reproduction-only medium, in otherwords, a block EP_map_for_HDMV( ) of the foregoing field CPI_type. Themap EP_map is a table that correlates reproduction times and addressesof a file for start positions of GOPs. In the example shown in FIG. 56,as a table that correlates PTS (Presentation Time Stamp) of MPEG and SPN(Source Packet Number) for start positions of GOPs, a database iscreated. SPN represents a source packet number that corresponds to abyte address from the beginning of a file.

The structure of the map EP_map for the recordable medium is almost thesame as the structure of the map EP_map for the reproduction-onlymedium. According to the embodiment, to reduce the data amount and speedup searches, coarse searches and fine searches are performed forindividual values. Thus, the internal structure of the map EP_map isdivided into two for loops corresponding to coarse searches and finesearches. Consequently, the map EP_map for the reproduction-type disc ismore complicated than a simple table “that correlates PTSs of the firstI pictures of GOPs and addresses in a file”.

A field EP_fine_table_start_address describes the position of a tableused for fine searches. The next for loop describes tables for coarsesearches. The for loop describes fields PTS_EP_coarse and SPN_EP_coarse.A field ref to_EP_fine_id describes a table number for fine searchesreferenced from coarse searches. The fields PTS_EP_coarse andSPN_EP_coarse describe high order bits of a PTS and an SPN.

The for loop is followed by a padding word. The padding word is followedby a for loop that describes fields PTS_EP_fine and SPN_EP_fine. Inaddition, the for loop describes a flag is_angle_change_point and afield I_end_position_offset. The flag is_angle_change_point describeswhether each EP point corresponds to an angle changeable point when theclip AV stream has a multiple angle structure (a second flag).

Next, the flag is_angle_change_point will be described. First of all,for easy understanding, how a clip AV stream is placed on a disc will bedescribed.

A clip AV stream is composed of a sequence (block) of data of whichlogical addresses on the disc 10 are successive. Hereinafter, a block ofdata as a clip AV stream of which logical addresses on the disc aresuccessive is referred to as an extent. FIG. 57 schematically shows anarrangement of extents on a disc. In an example shown in FIG. 57, oneclip AV stream is composed of a sequence of extents 601A, 601B, and601C. The lengths of the extents and the arrangement thereof areproperly controlled when the disc is produced.

Then, the extents 601A, 601B, and 601C are structured so that theysatisfy the minimum size rule. When the clip AV stream has been recordedon a disc 600, it is assured that data that is reproduced issuccessively supplied.

When one file is composed of a plurality of extents 601A, 601B, and 601Cas shown in FIG. 57, a reading operation for successively reading forexample one extent 601A and then the next extent 601B is repeated. Whenone extent 601A is read and then the next extent 601B is read, it isnecessary to change the number of rotations of the disc 600 and move anoptical pickup that composes a reading portion of the player for thedisc 600.

The maximum access time for which the optical pickup is moved on thedisc 600 is around 0.8 seconds. While the optical pickup is being moved,data cannot be obtained from the drive, which composes the disc readingportion. On the other hand, since video and audio data are successivelydecoded and reproduced, a mechanism for compensating the access time isrequired.

When one extent 601A and the next extent 601B are successively accessed,a jump takes place therebetween. When the byte length of the formerextent 601A is large, before a jump is preformed, a sufficient amount ofdata can be read from the extent 601A and stored in a buffer. Thus,while the jump is being performed, since the data stored in the bufferis supplied to the decoder, the data can be successively decoded.

In other words, if the size of the extent 601A from which the jump isperformed is sufficiently large, while the next extent 601B is beingjumped, it is assumed that the stream will be successively supplied.Thus, to store a sufficient amount of data to the buffer, the lowerlimit of the size of an extent needs to be restricted. The minimumextent size is defined as a proper value in accordance with the readrate of the disc 600 and the drive's access time. The condition forsuccessively supplying data can be determined depending on whether ornot data has been arranged in accordance with the minimum size rule forextents.

FIG. 58 shows an example of which a clip AV stream has been fragmentallyrecorded as for example extents 601D and 601E on a disc. To assure thatthe recorded clip AV stream is read at a predetermined bit rate from therecording medium in FIG. 58, the size of one extent should satisfy acondition given by the following formula (1).S×8/(S×8/Rud+Ts)>=Rmax  (1)

In the formula (1), “S” represents the size of an extent in bytes and“Ts” represents a full-stroke access time, namely the maximum accesstime, in seconds from one extent 601D to the next extent 601E. “Rud”represents a bit rate at which data is read from a disc. “Rmax”represents a bit rate of a clip AV stream. “Rud” and “Rmax” areexpressed in bits/second. “8” by which the extent size S is multipliedis used for a byte/bit conversion.

In other words, when data of a clip AV stream is successively arrangedso that the size of each of the extents 601D and 601E becomes S bytes orgreater, the sequence of the extents 601D and 601E can be seamlesslyreproduced.

The formula (1) can be modified as formula (2).S×8>=Rmax·Rud·Ts/(Rud−Rmax)  (2)

When a real value is calculated in accordance with the formula (2), ifthe bit rate Rmax of the clip AV stream is 28 (bits/second), assumingthat Rud=35 Mbps (Mega Bit per second) and Ts=0.8 seconds, the relationof S>=14 MB (Mega Byte) is satisfied. In other words, in the example,the minimum extent size S becomes 14 MB.

In the foregoing manner, when one file is successively read, thecondition for successively supplying data can be defined. This conditioncan be applied to a seamless angle switching function for seamlesslyswitching angles that are read in a multiple angle function.

Next, with reference to FIG. 59A and FIG. 59B, the multiple anglefunction will be described. As an example shown in FIG. 59A, themultiple angle function provides a region for a plurality ofreproduction paths (this region is referred to as a multiple angleblock). While the user is reproducing the region, he or she can freelyswitch one angle to another angle. When the same object is photographedby a plurality of cameras with different angles, such a multiple angleblock can be formed.

Pictures that compose a multiple angle block are not limited to the samescene. Alternatively, a multiple angle block may be composed of aplurality of pictures to be selectively displayed in the same period ona reproduction time base.

A multiple angle block is composed of one play item. In other words, oneplay item contains pictures of a plurality of angles. In the exampleshown in FIG. 59A, in a multiple angle block, one of three angles (angle(0), angle (1), and angle (2)) can be selected.

As an example shown in FIG. 59B, to shorten the access time for whichone angle is switched to another angle, streams that compose a multipleangle block are recorded in a special arrangement on the disc. Thisblock recorded in the special arrangement on the disc is referred to asan interleave block. One successive portion is referred to as aninterleave unit. An interleave unit is recorded at successive addressesof the disc. An interleave unit satisfies the condition for the minimumextent size. In an interleave block, interleave units are arranged onthe time base in accordance with angles.

When one angle is switched to another angle in each interleave unit,since a jump is performed after data of the minimum extent size is read,the foregoing condition for successively supplying data is satisfied.When the beginning of a GOP is matched with the beginning of aninterleave unit, since the MPEG decoding can be performed from thebeginning of an interleave unit, one angle can be seamlessly switched toanother angle.

Next, a position at which one angle can be seamlessly switched toanother angle will be described. It is clear that one angle cannot befreely switched to another angle at any byte position due to both thecharacteristic of an MPEG stream that is inter-frame compressed and thecondition for successively supplying data from the disc. As the simplestmethod, one angle is switched to another angle in each interleave unitthat satisfies the minimum extent size. In addition, when the beginningof an interleave unit is matched with the beginning of a GOP, namely anEP entry, an MPEG stream can be successively decoded.

When the number of angle switchable points is increased and the numberof interleave blocks is increased by interleaving, one file isfragmented. As a result, the amount of management information of thefile system increases. For example, in the Blu-ray disc file system,when a file is divided into a plurality of extents, the number of discregions increases. As a result, the database of the file system becomeslarge. As a result, the upper limit of the number of files that can berecorded adversely decrease.

Thus, according to an embodiment of the present invention, as shown inFIG. 60A and FIG. 60B, the size of one interleave unit is increased sothat the number of interleave units of one interleave block is decreasedand a plurality of angle switchable points are described in oneinterleave unit. Since an angle switchable point is a decodable startpoint, the angle switchable point is matched with one of EP points.

The foregoing flag is_angle_change_point represents whether or not an EPentry that points at the beginning of a GOP is matched with an angleswitchable point. The flag is_angle_change_point has a value as shown inFIG. 61. When the value of the flag is_angle_change_point is “1”, itrepresents that the EP entry is an angle switchable point. When thevalue of the flag is_angle_change_point is “0”, it represents that theEP entry is not an angle switchable point.

Whether or not an EP entry is a seamless angle switchable pointbasically depends on whether or not the EP entry and the preceding angleswitchable point are apart by the minimum extent size or greater. Inother words, the distance between EP entries for which one angle can beswitched to anther angel, of which the value of the flagis_angle_change_point is “1”, should be apart by the minimum extent sizeor greater.

Next, with reference to FIG. 60A and FIG. 60B, a seamless angelswitching operation using the flag is_angle_change_point will bedescribed. In FIG. 60A and FIG. 60B, points denoted by upward arrowmarks represent angle switchable points. As an example shown in FIG.60B, points denoted by upward arrow marks are EP entries that are angleswitchable points. At each of these EP entries, the value of the flagis_angle_change_point is “1”.

With reference to FIG. 60A, it is assumed that while one angle (0) isbeing reproduced, the user switches the angle (0) to the angle (1).Then, the player continuously reads a stream of the angle (0) until theclosest EP entry of which the value of the flag is_angle_change_point is“1”. Next, the player searches a clip information file for an EP entryof the angle (1) in synchronization with the obtained EP entry, obtainsthe byte position of the obtained EP entry, and starts reading thestream from the obtained byte position. With the foregoing operation,angles can be seamlessly switched.

In the reproduction path on the disc, at the position of which the valueof the flag is_angle_change_point is “1”, a jump is performed betweenangles.

Next, the case of which one angle is nonseamlessly switched to anotherangle will be described. Nonseamless angle switching is angle switchingof a discontinuity can take place in a picture. In the seamless angleswitching, if angle switching is designated, as described above, astream is reproduced until an angle switchable point. At the angleswitchable point, the angle switching is performed. In contrast, in thenonseamless angle switching, when angle switching is designated, anglescan be promptly switched without consideration of the condition forsuccessively supplying data and the beginning of a GOP. Thus, thenonseamless angle switching has an advantage of short switching time.

FIG. 62A and FIG. 62B show an example of a nonseamless multiple angleblock. In the nonseamless angle switching, since a discontinuity cantake place in a picture, it is not necessary to always move to anotherangle in synchronization with the current angle. For example, while aGOP of one angle is being reproduced, a jump can be performed from theangle to the beginning of the closest GOP of another angle, the GOPbeing earlier than the GOP of the original angle. As shown in FIG. 62A,when a jump is performed from the angle (0) to the angle (1), thebeginning of a GOP of the angle (1) is sought. In the example, after theangle (1) is slightly returned, it is reproduced. FIG. 62B shows areproduction path on the disc in that case.

On the other hand, a nonseamless multiple angle block should beseamlessly connected at the exit thereof. In other words, when angleswitching is not performed at all, like a regular reproduction, toimprove the quality of a reproduced picture, it is very important not tocause a discontinuity to take place at an entrance and an exit of amultiple angle block.

According to the embodiment of the present invention, with the settingof the flag is_angle_change_point, a nonseamless multiple angle block isseamlessly connected to the main part.

A seamless connection between the main part and an angle block can berelatively easily performed. In other words, when the end of the mainpart (the end of a play item immediately preceded by an entrance of anonseamless multiple angle block) satisfies the condition of the minimumextent size, the main part can be seamlessly connected to any angle.

On the other hand, in the vicinity of an exit of an angle block to themain part, when angles are switched in a path as shown in FIG. 63A, dataafter the last switched point to the end of the angle does not satisfythe minimum extent size. Thus, when a jump is performed at the exit ofthe multiple angle block, the condition for successively supplying datais not satisfied. Thus, the picture is paused. Alternatively, adiscontinuity takes place and for example the screen becomes black. FIG.63B shows a reproduction path on the disc in that case.

In the example shown in FIG. 63A, data from the position at which theangle (2) is switched to the angle (1) to the exit of the multiple angleblock does not satisfy the minimum extent size. Thus, when the angle (1)is moved to the main part, since the amount of data that is read for theangle (1) is insufficient, a discontinuity takes place in the picturethat is reproduced.

According to the embodiment of the present invention, to solve theproblem that takes place in the nonseamless angle switching, the flagis_angle_change_point is used for a nonseamless multiple angle block.While a nonseamless multiple angle block is being reproduced, whenangles are switched, a discontinuity can take place in the picture.Thus, the value of the flag is_angle_change_point is all “1's” as shownin FIG. 63B. In other words, a jump can be performed from any positionof an angle that is being reproduced. In addition, a reproduction can beperformed from any jumped position.

Next, the definition of the flag is_angle_change_point for a clip in anonseamless multiple angle block will be given. As described above, in aregion of which the value of the flag is_angle_change_point is “0”,while a picture is being reproduced, angle switching to another angle(jump to another angle) and returning to the reproduction position ofthe original angle (return to original angle) are prohibited. Incontrast, in a region of which the value of the flagis_angle_change_point is “1”, the “jump to another angle” and “return tooriginal angle” can be performed. In the vicinity of the exit of eachangle, at a predetermined number of positions, the value of the flagis_angle_change_point is set to “0”. In the region of which the value ofthe flag is_angle_change_point is set to “0”, the “jump to anotherangle” and “return to original angle” are prohibited. The size of theregion of which the value of the flag is_angle_change_point is set to“0” is equal to or greater than the minimum extent size.

Since the flag is_angle_change_point is set in such a manner,immediately before an exit of a nonseamless multiple angle block, the“jump to another angle” and “return to original angle” can beprohibited.

For example, as shown in FIG. 64B and FIG. 65B, the value of the flagis_angle_change_point is set to “0” in six EP entries on the rear endside of each interleave unit, whereas the value of the flagis_angle_change_point is set to “1” in the other EP entries of eachinterleave unit.

Next, methods for reproducing a nonseamless multiple angle block inaccordance with the value of the flag is_angle_change_point that hasbeen set in the foregoing manner will be described. In the first method,in a region of which the value of the flag is_angle_change_point hasbeen set to “0”, the angle switching is prohibited.

Next, with reference to FIG. 64A and FIG. 64B, the first method will bedescribed. As described above, in six EP entries on the rear end side ofeach interleave unit, the value of the flag is_angle_change_point is setto “0” (see FIG. 64B). As shown in FIG. 64A, when the reproductionposition is in the region of which the value of the flagis_angle_change_point has been set to “0”, the angle switching isprohibited. Even if the user issues an angle switching command in theregion, the player will ignore the command. In the example, the playerdoes not perform the angle switching. The player exits the multipleangle block and enters the main part play item. FIG. 64B shows areproduction path on the disc in that case.

In the second method, although the angle switching is permitted in aregion of which the value of the flag is_angle_change_point has been setto “0”, after the angle switching is performed, a jump is performed to aposition at which the value of the flag is_angle_change_point has beenset to “1”.

Next, with reference to FIG. 65A and FIG. 65B, the second method will bedescribed. As described above, in six EP entries on the rear end side ofeach interleave unit, the value of the flag is_angle_change_point is setto “0” (see FIG. 65B). As shown in FIG. 65A, at a position whosedistance to the exit of a multiple angle block is smaller than theminimum extent size, namely in a region of which the value of the flagis_angle_change_point has been set to “0”, if angle switching isdesignated, the reproduction position is returned to a region of whichthe value of the flag is_angle_change_point has been set to “1” and thereproduction is started from the region. FIG. 65B shows a reproductionpath on the disc in that case.

In any of the first and second methods, when a jump is performed at theexit of a multiple angle block, after data of the minimum extent size orgreater is read, the next play item is reproduced. Thus, a discontinuity(nonseamless) can be prevented from taking place at the exit of an angleblock.

In FIG. 64A and FIG. 64B, an interleave block composes a nonseamlessmultiple angle block. However, as shown in FIG. 65A and FIG. 65B, otherthan an interleave block can compose a nonseamless multiple angle block.

FIG. 66A, FIG. 66B, and FIG. 66C are functional block diagrams showingan example of a structure of a player decoder 100 according to anembodiment of the present invention. The player decoder 100 interpretsdata reproduced from a disc loaded into a drive device (not shown),outputs an AV stream, and allows the user to interactively operate theoutput AV stream.

All operations of the player decoder 100 are controlled by a CPU (notshown). Streams and data flows of individual portions of the playerdecoder 100 are monitored and controlled by the CPU.

When the disc is loaded into the drive device (not shown), as describedabove, the file “scenario.hdmv” and the file “entrylist.data” arereproduced. In accordance with the descriptions of the file“scenario.hdmv” and the file “entrylist.data”, other necessary files areread from the disc and thereby a content recorded on the disc isreproduced. For example, in accordance with the descriptions of the file“scenario.hdmv” and the file “entrylist.data”, moving picture datadisplayed on the moving picture plane 10, image data displayed on thesubtitle plane 11 and the graphics plane 12, a play list file, and soforth are read from the disc.

In the following description, among those data that is read from thedisc, streams such as moving picture data, sub pictures (subtitle data),and sound data that should be continuously processed are referred to asreal time streams. In contrast, non-real time data such as scenariofiles and play list files that are not required to be successivelyprocessed are referred to as store objects. The store objects are storedin a memory or the like and expanded thereon. Store objects are storedin the memory or the like, expanded, and processed when necessary.

The player decoder 100 has two systems of input channels that arechannel (1) and channel (2). A store object is input to an inputterminal 101 of the input channel (1). A real time stream is input to aninput terminal 202 of the input channel (2). Alternatively, a storeobject may be input to the input terminal 202. According to theembodiment, a real time stream and a part of a store object that areinput to the input terminal 202 are MPEG2 TSs.

When the rotation speed of the disc in the drive device is increased forexample twice and the read transfer speed of the disc is increased, thereading operations for two systems of the channels (1) and (2) from thedisc are performed in time division basis.

First of all, the system of the input channel (1) will be described. Astore object that is input to the input terminal 101 is input to aswitch circuit 102. When a program code of the file “scenario.hdmv” as astore object is input, the switch circuit 102 selects an output terminal102A. The input program code is stored in a code buffer 104. As anotherprogram, an HTML file, an ECMA script, or the like may be input.

When image data and audio data are input as a store object, the switchcircuit 102 selects an output terminal 102B. As a result, the inputimage data is input to a switch circuit 103. When a real time streamthat is input to the input terminal 202 does not contain image datadisplayed on the subtitle plane 11 or the graphics plane 12, the switchcircuit 103 selects an input terminal 103A. The image data and audiodata that are input from the switch circuit 102 are stored in a contentsbuffer 105.

Likewise, when image data displayed on the subtitle plane 11 or thegraphics plane 12 and audio data as a sound effect are contained in areal time stream that is input to the input terminal 202, the switchcircuit 103 selects an input terminal 103B. As a result, the imagedata/audio data is stored in the contents buffer 105. Store objectsstored in the code buffer 104 and the contents buffer 105 are read whennecessary and supplied to a multimedia engine 106.

The image data of the store object stored in the contents buffer 105 isalso supplied to a graphics decoder A 300 and a graphics decoder B 301through switch circuits 107 and 108, respectively.

In the example shown in FIG. 66A, FIG. 66B, and FIG. 66C, the graphicdecoder A 300 decodes PNG format image data. The graphic decoder B 301decodes JPEG format image data. Alternatively, the graphic decoder A 300and the graphic decoder B 301 may decode other format image data and/ora plurality of formats of image data.

The multimedia engine 106 comprises an XML parser 106A, a scriptinterpreter 106B, a graphic renderer 106C, a sound player 106D thatreproduces a sound effect, and a scenario file analyzing engine 106E.The multimedia engine 106 may be composed of independent hardware.Alternatively, the multimedia engine 106 may be accomplished by aprocess of a predetermined program that the foregoing CPU (not shown)executes.

The XML parser 106A has a function for parsing an XML (Extensible MarkupLanguage) document. In addition, the XML parser 106A can also parse anHTML document. An HTML document parsed by the XML parser 106A isconverted into a format that can be executed by the player decoder 100.The script interpreter 106B analyzes an ECMA script and converts it intoa format that can be executed by the player decoder 100. The graphicrenderer 106C decodes image data and obtains a format that can beexpanded on the subtitle plane 11 and the graphics plane 12. The soundplayer 106D reproduces audio data used for a button click sound and soforth.

The multimedia engine 106 performs processes for the XML parser 106A,the script interpreter 106B, and the graphic renderer 106C with a workmemory of a buffer 109. For example, the XML parser 106A and the scriptinterpreter 106B use a code buffer 109 a of the buffer 109. The graphicrenderer 106C uses a graphics buffer 109D of the buffer 109. The buffer109 further comprises a font buffer 109B that stores font data used todisplay a character string and a tree buffer 109C that stores the parsedresult of the HTML document by the XML parser 106A in a hierarchicaltree structure. The sound player 106D reproduces audio data stored inthe sound buffer 109E.

The multimedia engine 106 reads the scenario file “scenario.hdmv” and soforth stored in for example the code buffer 104. The scenario analyzingengine 104E analyzes a scenario in accordance with the description ofthe file that has been read. A drive device or the like (not shown) iscontrolled in accordance with the description of the analyzed scenario.Necessary files of moving picture data displayed on the moving pictureplane 10, image data displayed on the subtitle plane 11 and the graphicsplane 12, audio data, and so forth are read from the disc loaded intothe drive device. As a result, a content is reproduced.

Data that is stored in the code buffer 104 and the contents buffer 105can be held therein until the data becomes unnecessary. Thus, datastored in the code buffer 104 and the contents buffer 105 can berepeatedly read when necessary.

In addition, the multimedia engine 106 reads an ECMA script from thecode buffer 104. When necessary, the multimedia engine 106 reads anotherECMA script and an HTML document from the code buffer 104 in accordancewith the description of the ECMA script that has been read. In addition,the multimedia engine 106 reads image data from the contents buffer 105.

In addition, the multimedia engine 106 performs a demultiplexing processfor the plurality of types of input data, a JavaVM (Java (registeredtrademark) virtual machine) function, and so forth. Moreover, themultimedia engine 106 receives a user's input from operating means suchas a remote control commander, a pointing device, or the like (notshown) and performs a process in accordance with the user's input. Theuser's input is also supplied to the graphics decoder A 300, thegraphics decoder B 301, an audio decoder 118, an MPEG video decoder 120,and a system decoder 121 that will be described later.

Image data processed by the graphic renderer 106C is supplied to a subpicture plane 302 and a graphics plane 303 through switch circuits 130and 131, respectively. In this example, it is assumed that image datasupplied to the sub picture plane 302 and the graphics plane 303 are bitmap data of which image data in the PNG format, JPEG format, or the likehas been decoded by the graphic renderer 106C. Timing at which the imagedata is supplied to the planes 302 and 303 is controlled by themultimedia engine 106.

The sub picture plane 302 and the graphics plane 303 correspond to theforegoing subtitle plane 11 and graphics plane 12, respectively. Amoving picture plane 135 corresponds to the foregoing moving pictureplane 10. Each of the sub picture plane 302, the graphics plane 303, andthe moving picture plane 135 is composed of for example a frame memory.

The multimedia engine 106 also supplies a control signal that causes oneof the moving picture plane 135, the sub picture plane 302, and thegraphics plane 333 to be selected or them to be combined to apresentation processor 139 that will be described later. Likewise, themultimedia engine 106 supplies a control signal that controls an outputof an audio stream to a presentation processor 141 that will bedescribed later.

Next, the system of the input channel (2) will be described. A real timestream that is input as an MPEG2 TS to the input terminal 202 issupplied to the PID filter 110. The PID filter 110 extracts a PID(Packet Identification) from the MPEG2 TS transport stream and detectsan attribute of a stream contained in a transport packet. The PID filter110 separates the input real time stream into corresponding systems foreach transport packet in accordance with the attribute of the stream.

When a transport packet is a packet in which image data of a storeobject is contained, the transport packet is temporarily stored in abuffer TBn 111A. The transport packet is read at predetermined timingand input to the switch circuit 103 through the input terminal 103B thathas been selected. Thereafter, the transport packet is stored in thecontents buffer 105 through the switch circuit 103.

When the PID filter 110 has determined that the transport packetcontains PNG format data in accordance with the PID, the transportpacket is temporarily stored in a buffer TBn 111B and a buffer Bn 112B.The transport packet is read at predetermined timing and input to theswitch circuit 107 through an input terminal 107B that has beenselected. The transport packet is supplied to the graphics decoder A 300through the switch circuit 107.

The graphics decoder A 300 removes header information from the suppliedtransport packet, decodes PNG data contained in the transport packet,and obtains image data for subtitles or graphics. When the image data isused as subtitles, the image data is input to an input terminal 130B ofthe switch circuit 130 and expanded to the sub picture plane 302 throughthe switch circuit 130 at predetermined timing. Likewise, when the imagedata is used as buttons, since they are displayed on the graphics plane,the image data is input to an input terminal 131C of the switch circuit130 and expanded to the graphics plane 303 through the switch circuit131.

When the PID filter 110 has determined that a transport packet containsJPEG data in accordance with the PID, the transport packet istemporarily stored in a buffer TBn 111C and a buffer Bn 112C. Thetransport packet is read at predetermined timing, input to a switchcircuit 108 through an input terminal 108B that has been selected, andsupplied to the graphics decoder B 301 through the switch circuit 108.

The graphics decoder B 301 removes header information from the suppliedtransport packet, decodes JPEG data contained in the transport packet,and obtains bit map image data. When the image data is used assubtitles, the image data is input to an input terminal 130C of theswitch circuit 130 at predetermined timing and expanded to the subpicture plane 302 through the switch circuit 130. Likewise, when theimage data is used as buttons, the image data is input to an inputterminal 131B of the switch circuit 131 at predetermined timing andexpanded to the graphics plane 302 through the switch circuit 131.

When the PID filter 110 has determined that a transport packet containsaudio data in accordance with the PID, the transport packet istemporarily stored in a buffer TBn 111D and a buffer Bn 112D. Thetransport packet is read at predetermined timing and supplied to theaudio decoder 118. Audio data contained in the transport packet iscompression-encoded in accordance with a system based on for exampleDolby Digital.

The audio decoder 118 has for example a linear PCM (Pulse CodeModulation) audio decoder 119 that removes header information from theinput transport stream, decodes compression-encoded audio data containedin the transport packet, and finally obtains linear PCM audio data. Whenthe transport packet contains linear PCM audio data that has not beencompression-encoded, the data is directly input to the linear PCM audiodecoder 119. The linear PCM audio decoder 119 outputs the data withoutperforming any process.

The linear PCM audio data that is output from the audio decoder 118 isinput to the presentation processor 141 for audio. In the presentationprocessor 141, a predetermined sound effect and so forth are added tothe linear PCM audio data under the control of the multimedia engine 106and then obtained from an output terminal 142.

When the PID filter 110 has determined that a transport packet containsmoving picture data in accordance with the PID, the transport packet istemporarily stored in a buffer TBn 111E, a buffer MBn 113, and a bufferEBn 114, read at predetermined timing, and supplied to the MPEG videodecoder 120. The moving picture data contained in the transport packethas been compression-encoded in accordance with the MPEG2 system.

The MPEG video decoder 120 removes header information from the suppliedtransport packet, decodes moving picture data that has beencompression-encoded in accordance with the MPEG2 system, and obtainsbase band moving picture data.

The moving picture data that is output from the MPEG video decoder 120is input to an input terminal 124A of a switch circuit 124. In addition,the moving picture data is input to an input terminal 124B of the switchcircuit 124 through a buffer 123. In the switch circuit 124, the inputterminals 124A and 124B are selected at predetermined timing. Outputmoving picture data is expanded on the moving picture plane 134.

When the PID filter 110 has determined that the transport packetcontains system information in accordance with the PID, the transportpacket is supplied to the system decoder 121 through buffers TBn 111Fand Bsys 115. The system decoder 121 removes header information from thesupplied transport packet and extracts the system information therefrom.The system information is supplied to for example the CPU (not shown).

Image data on the sub picture plane 302 is supplied to a palette 304that corresponds to the foregoing palette table 22 shown in FIG. 17. Thepalette has 256 colors. The palette is referenced with an index. RGBdata is output. In addition, transparency data a1 is extracted. The RGBdata is converted into YCbCr data by an RGB/YCbCr converting circuit 306that corresponds to the foregoing RGB/YCbCr converting circuit 29 shownin FIG. 17. In addition to the transparency data a1, the YCbCr data issupplied to the presentation processor 139.

Image data on the graphics plane 303 is supplied to a palette 305 thatcorresponds to the foregoing palette table 26A shown in FIG. 17. As aresult, RGB data and transparent data a2 are output. The RGB data issupplied to an RGB/YCbCr converting circuit 307 that corresponds to theRGB/YCbCr converting circuit 26B shown in FIG. 17. As a result, thecolor system is converted from RGB (4:4:4) into YCbCr (4:4:4). Inaddition to the transparent data α2, the YCbCr data that is output fromthe RGB/YCbCr converting circuit 307 is supplied to the presentationprocessor 139.

An output of the moving picture plane 135 is supplied to thepresentation processor 139 through an up/down converter 138. The up/downconverter 138 is a circuit that converts the resolution of the image.The up/down converter 138 converts for example an HD (High Definition)image having a high resolution into an SD (Standard Definition) imagehaving a standard resolution.

The presentation processor 139 performs an alpha-blending process usingtransparency α1 of image data of the subtitle plane 11 (subtitle plane302) and transparency α2 of the graphics plane 12 (graphics plane 303)described in FIG. 17.

The presentation processor 139 combines image data of the moving pictureplane 135 and image data of the sub picture plane 302 in accordance withthe transparency α1 that has been set to the image data of the subpicture plane 502. In addition, the presentation processor 139 combinesthe image data of which the image data of the moving picture plane 135and the image data of the subtitle plane 302 have been combined andimage data of the graphics plane 303 in accordance with the transparencya2 that has been set to the image data of the graphics plane 303. Theimage data of which the image data of the graphics plane 303, the imagedata (subtitle data) of the sub picture plane 302, and the image data ofthe moving picture plane 135 have been combined is obtained from anoutput terminal 140.

The presentation processor 139 can perform an effect process for imagedata on real time basis.

In such a structure, when a content described and whose data isstructured according to the embodiment of the present invention isloaded into a drive device (not shown), the file “scenario.hdmv” and soforth are read. In accordance with the description of the file“scenario.hdmv”, a content recorded on the disc are reproduced. When theuser issues a command with the operating means (not shown), each portionof the drive device and the player decoder 100 are controlled by themultimedia engine 106. Data is reproduced in accordance with thecommand.

When an angle switching command is issued by the operating means (notshown), required files “scenario.hdmv”, “entrylist.data”, and so forthare referenced under the control of the multimedia engine 106. Inaccordance with information about a clip switchable point, the drivedevice (not shown) is controlled. In the foregoing manner, a readposition on the disc is changed so as to switch angles. In addition, theoperating means can issue a pause cancellation command for a stillpicture.

In the foregoing description, each portion of the player decoder 100 iscomposed of hardware. However, the present invention is not limited tosuch an example. For instance, the player decoder 100 can beaccomplished by a process of software. In this case, the player decoder100 can be operated on a computer device. In addition, the playerdecoder 100 can be accomplished by a combination of hardware andsoftware. For example, the audio decoder 118 and the MPEG video decoder120 may be composed of hardware. The rest of the player decoder 100 maybe composed of software.

A program that causes a computer device to execute the player decoder100 composed of only software or a combination of hardware and softwareis recorded on a recording medium for example a CD-ROM (CompactDisc-Read Only Memory) and supplied therewith. The CD-ROM is loaded intoa CD-ROM drive of the computer device. The program recorded on theCD-ROM is installed to the computer device. As a result, the foregoingprocess can be executed on the computer device. Since the structure ofthe computer device is well known, the description thereof will beomitted.

As described above, the present invention has an effect that aninteractive function causing reproduction to be changed in accordancewith the user's input can be accomplished by extending the blu-ray discstandard for recording and reproducing data for a prerecorded largecapacity disc.

In addition, according to the embodiment of the present invention, sinceinformation of a play list composing a title and a top menu is describedin a database, a desired title can be directly reproduced with a keyoperation of a remote controller or the like without need to select thedesired title on a screen. Moreover, a top menu screen can be invoked.

In addition, according to the embodiment of the present invention, sincea flag that represents whether or not angles can be switched isdescribed at the beginning of each decoding unit, a seamless angleswitching function free of a discontinuity at an angle switched pointcan be accomplished.

According to the embodiment of the present invention, since a flag thatrepresents whether or not a sub play item can be reproduced not insynchronization with a main play item is described, a BGM that is not insynchronization with a main path can be repeatedly reproduced.

The invention claimed is:
 1. A reproducing apparatus for reproducingcontent data recorded on a recording medium, the reproducing apparatuscomprising: reading means for reading from the recording medium a mainstream mainly reproduced, a substream reproduced as a substream of themain stream along therewith, and an information as a flag thatrepresents whether or not the substream should be repeatedly reproducednot in synchronization with the main stream; and reproducing means forcontrolling the reproduction of the substream in accordance with theinformation.
 2. The reproducing apparatus as set forth in claim 1,wherein the reproducing means is configured to repeatedly reproduce thesubstream until the reproduction of the main stream is finished, whenthe information represents that the substream should be repeatedlyreproduced.
 3. The reproducing apparatus as set forth in claim 1,wherein the substream includes only audio data.
 4. A reproducing methodfor reproducing content data recorded on a recording medium, thereproducing method comprising the steps of: reading from the recordingmedium a main stream mainly reproduced, a substream reproduced as asubstream of the main stream along therewith, and an information as aflag that represents whether or not the substream should be repeatedlyreproduced not in synchronization with the main stream; and controllingthe reproduction of the substream in accordance with the information. 5.A reproducing apparatus for reproducing content data recorded on arecording medium, the reproducing apparatus comprising: a readerconfigured to read from the recording medium a main stream mainlyreproduced, a substream reproduced as a substream of the main streamalong therewith, and an information as a flag that represents whether ornot the substream should be repeatedly reproduced not in synchronizationwith the main stream; and a controller configured to control thereproduction of the substream in accordance with the information.
 6. Astorage medium on which a reproducing program that can be read by acomputer device has been recorded in non-transitory form, thereproducing program configured to cause the computer device to execute areproducing method for reproducing content data recorded on a recordingmedium, the reproducing method comprising the steps of: reading from therecording medium a main stream mainly reproduced, a substream reproducedas a substream of the main stream along therewith, and an information asa flag that represents whether or not the substream should be repeatedlyreproduced not in synchronization with the main stream; and controllingthe reproduction of the substream in accordance with the information. 7.A storage medium on which content data has been recorded innon-transitory form, wherein a main stream mainly reproduced, asubstream reproduced as a substream of the main stream along therewith,and an information have been recorded on the recording medium, theinformation as a flag representing whether or not the substream shouldbe repeatedly reproduced not in synchronization with the main stream,and wherein the reproduction of the substream is controlled inaccordance with the information.
 8. The storage medium as set forth inclaim 7, wherein when the information represents that the substreamshould be repeatedly reproduced, the substream is repeatedly reproduceduntil the reproduction of the main stream is finished.
 9. The storagemedium as set forth in claim 7, wherein the substream includes onlyaudio data.